{"id":3798,"date":"2023-11-02T11:48:56","date_gmt":"2023-11-02T06:18:56","guid":{"rendered":"https:\/\/apboardsolutions.guru\/?p=3798"},"modified":"2023-11-10T16:08:46","modified_gmt":"2023-11-10T10:38:46","slug":"ap-ssc-10th-class-chemistry-important-questions-chapter-8","status":"publish","type":"post","link":"https:\/\/apboardsolutions.guru\/ap-ssc-10th-class-chemistry-important-questions-chapter-8\/","title":{"rendered":"AP SSC 10th Class Chemistry Important Questions Chapter 8 Structure of Atom"},"content":{"rendered":"

AP State Board Syllabus AP SSC 10th Class Physical Science Important Questions<\/a> Chapter 8 Structure of Atom.<\/p>\n

AP State Syllabus SSC 10th Class Chemistry Important Questions 8th Structure of Atom<\/h2>\n

10th Class Chemistry 8th Lesson Structure of Atom 1 Mark Important Questions and Answers<\/h3>\n

Question 1.
\nWrite the electronic configuration of chromium. (AP June 2016)
\nAnswrr:
\nThe electronic configuration of chromium is
\n1s\u00b22s\u00b22p6<\/sup>3s\u00b23p6<\/sup>4s\u00b93d5<\/sup> or [Ar] 4s\u00b93d5<\/sup><\/p>\n

Question 2.
\nOut of 3d and 4s, which has more (n + l) value? Explain. (AP June 2017)
\nAnswer:
\n1) 3d \u21d2 n + l \u21d2 3 + 2 \u21d2 5 (energy)
\n4s \u21d2 n + l \u21d2 4 + 0 \u21d2 4 (energy)<\/p>\n

2) Hence, ‘3d\u2019 has more (n + l) value than \u20184s\u2019.<\/p>\n

\"AP<\/p>\n

Question 3.
\nPrepare a question on nlx<\/sup> method. (AP SA-I:2018-19)
\nAnswer:<\/p>\n

    \n
  • How is nlx<\/sup> method useful.<\/li>\n
  • Explain the nlx<\/sup> method with an example.<\/li>\n<\/ul>\n

    Question 4.
    \nWhich colours do you observe when an iron rod is gradually heated to higher tem-peratures? (TS June 2015)
    \nAnswer:
    \nFirst iron turns into red (lower energy corresponding to higher wavelength) and as the temperature rises it glows and turns into orange, yellow, blue or even white respectively (higher energy and lower wavelength).<\/p>\n

    Question 5.
    \nWhich principle is not followed in writing the electronic configuration of 1s\u00b2 2s\u00b9 2p4<\/sup>? Give reasons. (TS June 2015)
    \nAnswer:
    \n1) Principle :
    \nAufbau principle is not followed in writing the electronic configuration of 1s\u00b2 2s\u00b9 2p4<\/sup>.<\/p>\n

    2) Reasons :
    \ni) According to Aufbau principle electron enters into orbital of lowest energy.
    \nii) Between 2s and 2p, 2s has least energy. So 2s must be filled before the electron has to enter 2p.<\/p>\n

    \"AP<\/p>\n

    Question 6.
    \nWrite the symbol of the outermost shell of magnesium (Z = 12) atom. How many electrons are present in the outermost shell of magnesium? (TS June 2017)
    \nAnswer:
    \nSymbol of the outermost shell of magnesium (3rd shell) = M
    \nNo. of electrons in outermost shell of Magnesium = 2.<\/p>\n

    Question 7.
    \nThe four quantum number values of the 21st electrons of scandium (Sc) are given in the following table. (TS March 2017)
    \n\"AP
    \nWrite the values of the four quantum numbers for the 20th electron of scandium (Sc) in the form of the table.
    \nAnswer:
    \n\"AP<\/p>\n

    Question 8.
    \nIf n = 3, mention the orbitals present in the shell and write maximum number of electrons in the shell. (TS March 2018)
    \n(OR)
    \nWrite the maximum number of electrons and number of orbitals in the shell, when n = 3.
    \nAnswer:<\/p>\n

      \n
    1. When n = 3, number of subshells = 3 (3s1<\/sub> 3p1<\/sub> 3d)<\/li>\n
    2. Number of orbitals = 9 (3s(1) 3p(3) 3d(5))<\/li>\n
    3. Maximum number of electrons (3s\u00b2 3p6<\/sup> 3d10<\/sup>) = 18<\/li>\n<\/ol>\n

      Question 9.
      \nWhat is dispersion?
      \nAnswer:
      \nThe splitting of light into different colours is called dispersion.<\/p>\n

      Question 10.
      \nWhat is an electromagnetic wave?
      \nAnswer:
      \nWhen electric field and magnetic fields are perpendicular to each other and at right angles to the direction of propagation of wave is formed. Such a wave is called electromagnetic wave.<\/p>\n

      \"AP<\/p>\n

      Question 11.
      \nWhat is a Zeeman effect?
      \nAnswer:
      \nThe splitting of spectral lines in the presence of magnetic field is called Zeeman effect.<\/p>\n

      Question 12.
      \nWhat is a spectrum?
      \nAnswer:
      \nGroup of wavelengths is called spectrum (or) A collection of dispersed light giving its wavelength composition is called a spectrum.<\/p>\n

      Question 13.
      \nWhat is speed of electromagnetic wave?
      \nAnswer:
      \nIt is equal to speed of light, i.e. 3 x 108<\/sup> ms-1<\/sup><\/p>\n

      Question 14.
      \nWhich colour has highest wavelength and which colour has least wavelength on visible spectrum?
      \nAnswer:
      \nThe colour that has highest wavelength in visible spectrum is red and least wavelength is violet.<\/p>\n

      \"AP<\/p>\n

      Question 15.
      \nIf n = 5, then what is the maximum value for l?
      \nAnswer:
      \nThe maximum value for l is 4.<\/p>\n

      Question 16.
      \nIf l = 4, what is the number erf values for ml<\/sub>?
      \nAnswer:
      \nml<\/sub> = 2l + 1 = 2(4) +1=9.<\/p>\n

      Question 17.
      \nWhat are the values of ms<\/sub>?
      \nAnswer:
      \n\u00bd or – \u00bd<\/p>\n

      Question 18.
      \nWhat is electronic configuration?
      \nAnswer:
      \nDistribution of electrons in shells, sub-shells and orbital in an atom is known as electronic configuration.<\/p>\n

      Question 19.
      \nWhat is Heisenberg’s principle of uncertainty?
      \nAnswer:
      \nIt is not possible to find the exact position and velocity of electron simultaneously.<\/p>\n

      Question 20.
      \nGive ascending order of various atomic orbitals according to Moeller diagram.
      \nAnswer:
      \n1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s < 4d < 5d < 6p < 7s < 5f < 6d < 7p < 8s.<\/p>\n

      Question 21.
      \nWhat is Hund’s Rule?
      \nAnswer:
      \nElectron pairing in orbitals starts only when all available empty orbitals of the same energy are singly occupied.<\/p>\n

      \"AP<\/p>\n

      Question 22.
      \nWhat is Planck’s equation?
      \nAnswer:
      \nPlanck’s equation is E = hv.
      \nE = Energy of the radiation
      \nh = Planck’s constant = 6.625 \u00d7 10-34<\/sup> J
      \nv = Frequency of radiation.<\/p>\n

      Question 23.
      \nWhat is electromagnetic spectrum?
      \nAnswer:
      \nElectromagnetic waves can have a wide variety of wavelengths. The entire range of wavelengths is known as the electromagnetic spectrum.<\/p>\n

      Question 24.
      \nWhat is wavelength?
      \nAnswer:
      \nThe distance from one wave peak to the next is called wavelength (\u03bb).<\/p>\n

      Question 25.
      \nWhat is frequency?
      \nAnswer:
      \nThe number of wave peaks that pass by a given point per unit time is called frequency.<\/p>\n

      \"AP<\/p>\n

      Question 26.
      \nWhen are electromagnetic waves produced?
      \nAnElectromagnetic waves are produced when an electric charge vibrates.<\/p>\n

      Question 27.
      \nWhich is the example for line spectrum?
      \nAnswer:
      \nThe atomic spectrum of hydrogen atom.<\/p>\n

      Question 28.
      \nWhich model explains fine spectrum of atom?
      \nAnswer:
      \nBohr – Sommerfeld model.<\/p>\n

      Question 29.
      \nHow are wavelength and velocity of light related?
      \nAnswer:
      \nc = v\u03bb
      \nwhere
      \nc = velocity of light,
      \nv = frequency of light,
      \n\u03bb = wavelength of light.<\/p>\n

      Question 30.
      \nGive the equation which gives electromagnetic energy (light) that can have only Certain discrete energy values.
      \nAnswer:
      \nE = hv
      \nE = Energy of light
      \nh = Planck’s constant = 6.62 5 \u00d7 10-27<\/sup> erg sec or 6.625 \u00d7 10-34<\/sup> Joule-sec
      \nv = Frequency of radiation
      \nThis equation is called Planck’s equation.<\/p>\n

      \"AP<\/p>\n

      Question 31.
      \nWhich group elements are called Noble gases?
      \nAnswer:
      \nVIII A group or 18th group elements are called inert gases (or) Noble gases.<\/p>\n

      Question 32.
      \nWhich elements are highly stable?
      \nAnswer:
      \nNoble gases are highly stable.<\/p>\n

      Question 33.
      \nWrite the set of quantum numbers for the electrons in a 3pz<\/sub> orbital.
      \nAnswer:
      \n\"AP<\/p>\n

      Question 34.
      \nWhat is the difference between an orbit and orbital?
      \nAnswer:
      \nAn orbit is a well defined path of electron that revolves around the nucleus.<\/p>\n

      An orbital is the space around the nucleus, where the probability of finding electrons is maximum.<\/p>\n

      Question 35.
      \nWhat are the factors which influence electromagnetic energy?
      \nAnswer:
      \nElectromagnetic energy depends on two factors<\/p>\n

        \n
      1. wavelength<\/li>\n
      2. frequency.<\/li>\n<\/ol>\n

        Question 36.
        \nWhat is a wave?
        \nAnswer:
        \nThe disturbance occurred in a medium is called wave.<\/p>\n

        \"AP<\/p>\n

        Question 37.
        \nWhen cupric chloride is kept in non-luminous flame then what is the colour of flame?
        \nAnswer:
        \nGreen colour.<\/p>\n

        Question 38.
        \nIf the colours gradually changes there are no sharp boundaries in between them, then what is the name given to that type of spectrum?
        \nAnswer:
        \nContinuous spectrum of emission.<\/p>\n

        Question 39.
        \nWhat is the information given by magnetic orbital quantum numbers?
        \nAnswer:
        \nOrientation of orbitals in space.<\/p>\n

        Question 40.
        \nHow many orbitals are present in a sub-shell?
        \nAnswer:
        \nThe number of orbitals are present in a sub-shell is n\u00b2\u00a0(where n is principal quantum number).<\/p>\n

        Question 41.
        \nWhat happens when an object is suitably excited by heating?
        \nAnswer:
        \nLight is emitted by the object.<\/p>\n

        Question 42.
        \nWhat is meant by Aufbau?
        \nAnswer:
        \nThe German word Aufbau means building up.<\/p>\n

        Question 43.
        \nWhich elements are examples for Noble gases?
        \nAnswer:
        \nHelium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe) and Radon (Rn) are examples for Noble gases.<\/p>\n

        Question 44.
        \nWhich element has duplet configuration?
        \nAnswer:
        \nHelium (1s\u00b2)<\/p>\n

        \"AP<\/p>\n

        Question 45.
        \nWrite the set of quantum number for the added electron of oxygen atom.
        \nAnswer:
        \nConfiguration of oxygen is 1s\u00b2 2s\u00b2 2p4<\/sup>.
        \nThe added electron is 4th in the 2p.
        \nThe set of quantum numbers (2, 1, -1, -\u00bd)<\/p>\n

        Question 46.
        \nCan we apply c = v\u03bb, to sound waves?
        \nAnswer:
        \nYes. It is a universal relationship and applies to all waves.<\/p>\n

        Question 47.
        \nWhat is the value of Planck’s constant?
        \nAnswer:
        \nThe value of Planck’s constant is 6.626 \u00d7 10-34<\/sup> Js.<\/p>\n

        Question 48.
        \nWhy do different elements emit different flame colours when heated by the same non-luminous flame?
        \nAnswer:’
        \nThe light emitted by different kind of atoms is different because the excited states electrons will go are different.<\/p>\n

        Question 49.
        \nHow many values can ‘l’ have for n = 4?
        \nAnswer:
        \nIf n = 4, l can take values 0, 1, 2, 3. So there are four values.<\/p>\n

        Question 50.
        \nWrite the four quantum numbers for the differentiating electrons of lithium (Li) atom.
        \nAnswer:
        \nThe electronic configuration of lithium is 1s\u00b2 2s\u00b9. So differentiating electron enters into 2s. The values of four quantum numbers are as given below.
        \n\"AP<\/p>\n

        Question 51.
        \nWrite four quantum numbers for 2p\u00b9 electrons.
        \nAnswer:
        \nThe four quantum numbers for 2p are
        \n\"AP<\/p>\n

        Question 52.
        \nWhich rule is violated in the following electronic configuration?
        \n\"AP
        \nAnswer:
        \nThe rule violated is Hund’s rule.<\/p>\n

        Question 53.
        \nHow many maximum number of electrons that can be accommodated in N principle energy shell?
        \nAnswer:
        \nFor N shell n = 4.
        \nThe maximum number of electrons accommodated in a shell is 2n\u00b2.
        \n\u2234 A maximum of 32 electrons can be filled in N shell.<\/p>\n

        \"AP<\/p>\n

        Question 54.
        \nHow many maximum number of electrons that can be accommodated in a ‘l’ sub-shell?
        \nAnswer:
        \nl sub-shell has 3 orbitals. Each orbital accommodates 2 electrons. So 6 electrons can be filled in l sub-shell.<\/p>\n

        Question 55.
        \nHow many maximum number of electrons can be accommodated in ‘d’ sub-shell?
        \nAnswer:
        \nd sub-shell has 5 orbitals. So 10 electrons can be filled in d sub-shell.<\/p>\n

        Question 56.
        \nHow many sub-shells present in a ‘M’ principal energy shell?
        \nAnswer:
        \nFor M shell n = 3
        \nThe number of sub-shells in M shell is 3.<\/p>\n

        Question 57.
        \nHow many spin orientations are possible for an electron in s-orbital?
        \nAnswer:
        \nThe spin quantum number values for electrons are \u00bd or -\u00bd. So 2 spin orientations are possible.<\/p>\n

        Question 58.
        \nWrite valence electronic configuration of element which has the following set of quantum numbers.
        \nAnswer:
        \n\"AP
        \nn = 3 indicates 3rd orbit and l = 1 indicates p orbital and there is one electron in p orbital. So the valence electron configuration is 3p\u00b9.<\/p>\n

        Question 59.
        \nHow many unpaired electrons are present in chromium?
        \nAnswer:
        \nThe electronic configuration of chromium 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6 4s\u00b9 3d5<\/sup>.
        \n\"AP
        \nThe number of unpaired electrons = 6.<\/p>\n

        Question 60.
        \nFind the four quantum number values of 3rd<\/sup> and 4th<\/sup> electrons of Beryllium.
        \nThe electronic configuration of Beryllium is 1s\u00b2 2s\u00b2.
        \n\"AP<\/p>\n

        Question 61.
        \nWhat is the n + l value of 4f orbital?
        \nAnswer:
        \nFor 4f orbital n = 4 and f orbital l = 3.
        \n\u2234 n + l = 4 + 3 = 7<\/p>\n

        Question 62.
        \nWhen you heat iron rod first it turns red. Why?
        \nAnswer:
        \nIron turns into red because red has higher wavelength. So it has lower energy which is emitted by iron.<\/p>\n

        \"AP<\/p>\n

        Question 63.
        \nWhat is the significance of Planck’s proposal?
        \nAnswer:
        \nElectromagnetic energy can be gained or lost in discrete values and not in a continuous manner.<\/p>\n

        Question 64.
        \nWhen do you see an emission line?
        \nThe energy emitted by an electron is seen in the form of an electromagnetic energy and when the wavelength is. in the visible region it is visible as an emission line.<\/p>\n

        Question 65.
        \nHow many elliptical orbits are there in 4th<\/sup> orbit of Sommerfeld?
        \nAnswer:
        \nThe number of elliptical orbits in 4th<\/sup> orbit of Sommerfeld is 3.<\/p>\n

        Question 66.
        \nWhy is spin quantum number introduced?
        \nAnswer:
        \nWhen we observe spectrum of yellow light by using high resolution spectroscope it has very closely spaced doublet. Similar patterns are shown by Alkali and Alkaline earth metals. In order to account this spin quantum number is introduced.<\/p>\n

        Question 67.
        \nWhich of the following magnetic quantum number values is not possible for 3d orbital?
        \na) – 2
        \nb) – 1
        \nc) 0
        \nd) 4
        \nAnswer:
        \nFor d orbital the possible m; values – 2, – 1, 0, 1, 2. So the value 4 is not possible.<\/p>\n

        Question 68.
        \nIf an element has 11 electrons in its M shell, then what is the name of element and its atomic number?
        \nAnswer:
        \nThe electronic configuration of element is 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup> 4s\u00b2 3d3<\/sup>.
        \n[M shell electrons = 2 + 6 + 3=11]<\/p>\n

        So the element is Titanium.<\/p>\n

        Question 69.
        \nThe wave length of a wave is 100 nm. Find its frequency.
        \nAnswer:
        \n\"AP<\/p>\n

        10th Class Chemistry 8th Lesson Structure of Atom 2 Marks Important Questions and Answers<\/h3>\n

        Question 1.
        \nExplain Hund’s Rule with an example. (TS March 2016) (AP SA-1:2018-19)
        \nAnswer:
        \nHund’s Rule :
        \nAccording to this rule electron pairing in orbitals starts only when all available empty orbitals of the same energy are singly occupied.<\/p>\n

        (1) Ex :<\/p>\n

          \n
        1. The configuration of carbon atom (Z = 6) is 1s\u00b2 2s\u00b2 2p\u00b2.<\/li>\n
        2. The first four electrons go into the 1s and 2s orbitals.<\/li>\n
        3. The next two electrons go into 2px<\/sub> and 2py<\/sub> orbitals.
          \n\"AP<\/li>\n
        4. But, they do not pair in 2px<\/sub> orbital.<\/li>\n<\/ol>\n

          (2) Ex :<\/p>\n

            \n
          1. In oxygen atom (8<\/sub>O), distribution of electrons is given below.<\/li>\n
          2. \"AP<\/li>\n
          3. Here, pairing of electrons in 2px orbital takes place after, 2px<\/sub>, 2py<\/sub> and 2pz<\/sub> orbitals are filled with a single electron.<\/li>\n<\/ol>\n

            Question 2.
            \nThe electronic configuration of Sodium is 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b9. (AP March 2017)
            \nWhat information that it gives?
            \nAnswer:<\/p>\n

              \n
            1. Its atomic number is 11<\/li>\n
            2. It is s-block element<\/li>\n
            3. It is in 3rd period \u2019<\/li>\n
            4. It is in 1st group<\/li>\n
            5. Its valency is 1<\/li>\n
            6. Number of valency electrons are 1<\/li>\n
            7. It can form uni positive ion<\/li>\n
            8. It can form ionic bond, 9. It is metal.<\/li>\n<\/ol>\n

              Question 3.
              \nExplain the principle which describes the arrangement of electrons in degenerate orbitals.
              \nAnswer:
              \nAccording to Hund’s rule the degenerate orbitals are occupied with one electron each before pairing of electron starts.
              \nEx : Electronic configuration of carbon is 1s\u00b2 2s\u00b2 2p\u00b2
              \n\"AP
              \nthe last two electrons will enter into separate 2p orbitals.<\/p>\n

              Question 4.
              \nName the principle, which says an orbital can hold only 2 electrons and explain. (AP March 2018)
              \nAnswer:<\/p>\n

                \n
              • Name of the principle : Pauli’s exclusion principle.<\/li>\n
              • No, two electrons in an orbital can have all four quantum numbers same.<\/li>\n
              • It says there is a chance to hold only 2 electrons, one rotates in clockwise direction (+\u00bd)other rotates in anticlock wise direction (-\u00bd).<\/li>\n<\/ul>\n

                \"AP<\/p>\n

                Question 5.
                \nFor a better understanding about the electronic configuration in an atom, the teacher wrote shorthand notation nlx<\/sup> on the blackboard.
                \nLooking at this notation, what could be the probable questions that generate in the student’s mind? Write any two of them. (TS March 2015)
                \nAnswer:<\/p>\n

                  \n
                1. What n, l, x indicates related to atoms?<\/li>\n
                2. How nlx<\/sup> indicates the position of the electrons in the atom?<\/li>\n<\/ol>\n

                  Question 6.
                  \nWrite the \u2018Octet Rule\u2019. How does Mg (12) get stability while reacting with chlorine as per this rule? (TS June 2017)
                  \nAnswer:
                  \nOctet Rule :
                  \nThe atoms of elements tend to undergo chemical changes that help to leave their atoms with eight outer – shell electrons.<\/p>\n

                  Magnesium atom looses 2 electrons and get 8 electrons in its outermost shell as Neon. So that it gets stability.<\/p>\n

                  Question 7.
                  \nWrite the electronic configuration of the atom of an element having atomic number 11. Write the names of the rules and the laws followed by you in writing this electronic configuration. (TS March 2017)
                  \nAnswer:
                  \n1s\u00b22s\u00b22p6<\/sup>3s\u00b9.
                  \n(OR)
                  \nPrinciples followed :<\/p>\n

                    \n
                  1. Aufbau principle.<\/li>\n
                  2. Hund’s Rule.<\/li>\n
                  3. Pauli Exclusion Principle<\/li>\n<\/ol>\n

                    Question 8.
                    \nThe electron enters into 4s orbital after filling 3p orbital but not into 3d. Explain the reason (TS March 2018)
                    \nAnswer:
                    \nBased on (n+l) values energy value of 3d orbitals is 3 + 2 = 5, energy value of 4s orbitals is 4 + 0 = 4
                    \nThe energy level of 4s orbital is less than the 3d orbital according to the Aufbau principle electron enters into lower energy orbital first.
                    \nThats why electrons enters into 4s orbital after filling 3p, but not into 3d.<\/p>\n

                    \"AP<\/p>\n

                    Question 9.
                    \nWrite the electronic configuration of Na+<\/sup> and Cl–<\/sup>.
                    \nAnswer:
                    \nElectronic Configuration of Na+<\/sup> is 1s\u00b2 2s\u00b2 2p6<\/sup> and Cl–<\/sup> is 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup>.<\/p>\n

                    Question 10.
                    \nObserve the given table and answer the following questions. (TS March 2019)<\/p>\n\n\n\n\n\n\n
                    Sl.No.<\/td>\nElectron Configuration<\/td>\n<\/tr>\n
                    1.<\/td>\n1s2<\/sup> 2s2<\/sup> 2p6<\/sup> 3s2<\/sup> 3p3<\/sup><\/td>\n<\/tr>\n
                    2.<\/td>\n1s2<\/sup> 2s2<\/sup> 2p6<\/sup> 3s2<\/sup> 3p6<\/sup> 4s2<\/sup><\/td>\n<\/tr>\n
                    3.<\/td>\n1s2<\/sup> 2s2<\/sup> 2p6<\/sup> 3s2<\/sup> 3p6<\/sup><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                    1) Mention the divalent element name.
                    \n2) Name the element belongs to 3rd<\/sup> period and VA Group.
                    \nAnswer:<\/p>\n

                      \n
                    1. Name of the divalent element in the table is Calcium.<\/li>\n
                    2. Name of the element which belongs to 3rd<\/sup> period and VA Group is Phosphorous.<\/li>\n<\/ol>\n

                      Question 11.
                      \nYour friend is unable to understand nlx<\/sup>. What questions will you ask him to understand nlx<\/sup> method? (AP SCERT: 2019-20)
                      \nAnswer:<\/p>\n

                        \n
                      1. What is nlx<\/sup> method?<\/li>\n
                      2. Where does it use ?<\/li>\n
                      3. What is meant by ‘n’, 7′ and ‘x’?<\/li>\n
                      4. How can we use nlx<\/sup> method in the writing of electronic configuration?<\/li>\n<\/ol>\n

                        Question 12.
                        \nWhy do valency electrons involve in bond formation, than electrons of inner shells? (AP SCERT: 2019-20)
                        \nAnswer:<\/p>\n

                          \n
                        1. When two atoms come sufficiently close together the valence electrons of each atom experience the attractive force of the nucleus in the other atom.<\/li>\n
                        2. The nucleus and the electrons in the inner shell remain unaffected when atoms come close together.<\/li>\n
                        3. The electrons in outer most shell of an atom get affected.<\/li>\n
                        4. Thus electrons in valence shell are responsible for the formation of bond between atoms.<\/li>\n<\/ol>\n

                          Question 13.
                          \nExplain Pauli’s exclusion principle with an example. (AP SA-I:2019-20)
                          \nAnswer:
                          \nPauli’s exclusion principle :
                          \nNo two electrons of the same atom can have all four quantum numbers the same. If n, l and ml<\/sub> are same for two electrons, then ms<\/sub> must be different.
                          \nSuppose take the example of Helium atom.
                          \nThe four quantum numbers for two electrons in the Helium atom given below.
                          \n\"AP<\/p>\n

                          We can observe from the table that three of the quantum numbers are same but fourth quantum number is different. The electronic configuration of Helium atom is\u00b2 \u2191\u2193. So the maximum number of electrons filled in an orbital is 2.<\/p>\n

                          Question 14.
                          \nExplain Aufbau principle. (AP SA-I:2019-20)
                          \nAnswer:
                          \nAufbau principle :<\/p>\n

                            \n
                          1. In the ground state the electronic configuration can be built up by placing electrons in the lowest available orbitals until the total number of electrons added is equal to atomic number.<\/li>\n
                          2. Thus orbitals are filled in the order of increasing energy.<\/li>\n
                          3. Electrons are assigned to orbitals in order of increasing value of n + l.<\/li>\n
                          4. For sub-shells with the same value of n + l, electrons are assigned first to the subshell with lower n.<\/li>\n<\/ol>\n

                            \"AP<\/p>\n

                            Question 15.
                            \nThe electronic configuration of an atom is as follows 1s\u00b2 2s\u00b2 2p\u00b2.
                            \na) Which element’s atom is it?
                            \nb) Which orbital is the last electron in?
                            \nc) When excited what could be the number of lone \/ single electrons in this atom?
                            \nd) What is the value of principal quantum numbers of two electrons in the first box?
                            \nAnswer:
                            \nGiven electronic configuration of atom is 1s\u00b2 2s\u00b2 2p\u00b2.
                            \na) The element is carbon.
                            \nb) The valence electron enters 2p orbital.
                            \nc) In excited state the electron in 2s orbital enters 2p orbital. So it has 4 unpaired electrons.
                            \nd) The value of principal quantum number is 1.<\/p>\n

                            Question 16.
                            \nDraw the table which gives the information about the quantum numbers and the number of the quantum states.
                            \nAnswer:
                            \n\"AP<\/p>\n

                            Question 17.
                            \nExplain briefly about spin quantum number.
                            \nAnswer:<\/p>\n

                              \n
                            • This gives spin of the electrons about their own axes. It is denoted by ms.<\/li>\n
                            • This quantum number refers to the two possible orientations of the spin of an electron, one clockwise and the other anti-clockwise spin.<\/li>\n
                            • These are represented by +\u00bd -\u00bd and .<\/li>\n<\/ul>\n

                              Question 18.
                              \nWrite electronic configurations of following elements,
                              \na) Hydrogen
                              \nb) Helium
                              \nc) Lithium
                              \nd) Beryllium
                              \ne) Boron
                              \nAnswer:
                              \n\"AP<\/p>\n

                              Question 19.
                              \nWhat does a line spectrum tell us about the structure of an atom?
                              \nAnswer:
                              \nThe electrons in ground state i.e. lowest, energy state absorb energy and move into excited state where they are unable to stay for long periods so lose the energy and come back to the ground state. The emitted radiation appears as line in line spectrum.<\/p>\n

                              Question 20.
                              \nWhat are the spins of electrons in Helium atom?
                              \nAnswer:
                              \nThe quantum numbers for two electrons of Helium are given below as per Pauli’s exclusive principle.
                              \n\"AP
                              \nThree of quantum numbers are same. So fourth must be different so the two electrons have anti-parallel spins.<\/p>\n

                              Question 21.
                              \n1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup> 3d10<\/sup> 4s\u00b9 is the electronic configuration of Cu (Z = 29). Which rule is violated while writing this configuration? What might be the reason for writing this configuration?
                              \nAnswer:
                              \nThe rule violated is Aufbau principle. The elements which have half filled or completely filled orbitals have greater stability. So copper can get stability by transferring one electron from 4s to 3d (their energies are close to each other).<\/p>\n

                              So the electronic configuration of copper is 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup> 3d10<\/sup> 4s\u00b9, not 1s\u00b2 2s\u00b2 2p 3s\u00b2 3p6<\/sup> 3d9<\/sup> 4s\u00b2.<\/p>\n

                              Question 22.
                              \nWhy are chromium and copper exceptions to electronic configuration?
                              \nAnswer:
                              \nElements which have half-filled or completely filled orbitals have greater stability. So in chromium and copper the electrons in 4s and 3d redistribute their energies to attain stability by acquiring half-filled and completely filled d orbitals.<\/p>\n

                              Hence the actual electronic configurations of chromium and copper are as follows.
                              \n\"AP<\/p>\n

                              Question 23.
                              \nDistinguish between emission and absorption spectrum.
                              \nAnswer:<\/p>\n\n\n\n\n\n\n
                              Emission spectrum<\/td>\nAbsorption spectrum<\/td>\n<\/tr>\n
                              1) The spectrum produced by emitted radiation is called emission spectrum.<\/td>\n1) The spectrum produced by absorption of radiation is called absorption spectrum.<\/td>\n<\/tr>\n
                              2) The emission spectrum contains bright lines on the dark back-ground.<\/td>\n2) The absorption spectrum contains dark lines on the bright back-ground.<\/td>\n<\/tr>\n
                              3) The emission spectrum corresponds the radiation emitted when an excited electron comes back to the ground state.<\/td>\n3) The absorption spectrum corresponds the radiation absorbed in exciting an electron from lower to higher energy levels.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                              Question 24.
                              \nDraw a table which will give the relationship between l values and number of orbitals and name of sub-shell and maximum number of electrons.
                              \nAnswer:
                              \n\"AP<\/p>\n

                              Question 25.
                              \nDistinguish between line and band spectrum.
                              \nAnswer:<\/p>\n\n\n\n\n\n\n
                              Line spectrum<\/td>\nBand spectrum<\/td>\n<\/tr>\n
                              1) The spectrum has sharp distinct lines.<\/td>\n1) The spectrum has many closed, spaced lines.<\/td>\n<\/tr>\n
                              2) The spectrum is characteristic of atoms and is also called atomic spectrum.<\/td>\n2) The spectrum is characteristic of molecules is also called molecular spectrum.<\/td>\n<\/tr>\n
                              3) The spectrum is given by inert gases, metal vapours and atomised non-metals.<\/td>\n3) The spectrum is given by hot metals and molecular non-metals.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                              Question 26.
                              \nWhat is Dispersion of light? Explain a natural example of dispersion of light.
                              \nAnswer:
                              \nDispersion:
                              \nSplitting of white light into colours (VIBGYOR) is called Dispersion of light.<\/p>\n

                              The natural example for dispersion of light is formation of Rainbow. It is caused by dispersion of sunlight by tiny water droplets present in atmosphere which act as small prisms.<\/p>\n

                              \"AP<\/p>\n

                              Question 27.
                              \nWien is an electromagnetic wave produced? Write about characteristics of electromagnetic wave.
                              \nAnswer:
                              \nElectromagnetic wave is produced when an electric charge vibrates (moves back and fortn).<\/p>\n

                              Characteristics of electromagnetic waves :<\/p>\n

                                \n
                              1. Efectric field and magnetic fields are perpendicular to each other and at right angles to direction of propagation of wave.<\/li>\n
                              2. It travels with speed of light i.e., 3 \u00d7 108<\/sup> ms-1<\/sup>.<\/li>\n
                              3. Electromagnetic energy is characterized by wavelength (\u03bb) and frequency (v). The relation is given by c = v\u03bb.<\/li>\n<\/ol>\n

                                Question 28.
                                \nThe valence electron configuration of element is given as 4s\u00b9. Then give the following information.
                                \n1) What is the name of that element?
                                \n2) What is the outermost orbit of element?
                                \n3) What is ‘l’ value of outermost sub-shell?
                                \n4) What is the atomic number of element?
                                \nAnswer:<\/p>\n

                                  \n
                                1. Potassium.<\/li>\n
                                2. N<\/li>\n
                                3. The outermost sub-shell is 4s its l value is ‘O’.<\/li>\n
                                4. Its electronic configuration is 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup> 4s\u00b9. So its atomic number is 19.<\/li>\n<\/ol>\n

                                  Question 29.
                                  \nWrite all the quantum numbers for valance electron of sodium.
                                  \nAnswer:<\/p>\n

                                    \n
                                  1. The electronic configuration of sodium is 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b9.<\/li>\n
                                  2. The valance orbital is 3s.<\/li>\n
                                  3. The quantum numbers for this orbital is
                                    \n\"AP<\/li>\n<\/ol>\n

                                    Question 30.
                                    \nGive electronic configurations of following elements.
                                    \na) Sodium
                                    \nb) Phosphorous
                                    \nAnswer:
                                    \nSodium – 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b9
                                    \nPhosphorous – 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p\u00b3<\/p>\n

                                    Question 31.
                                    \nWhy does nitrogen has more chemical stability when compared with oxygen?
                                    \nAnswer:
                                    \nThe electronic configurations of Nitrogen and Oxygen are as follows.
                                    \n\"AP
                                    \nNitrogen has half filled 2p\u00b3 configuration. So it has greater chemical stability when compared with Oxygen.<\/p>\n

                                    Question 32.
                                    \nRamu gave electronic configuration of potassium as 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup> 3d\u00b9 whereas Ravi expressed the configuration as 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup> 4s\u00b9. Who gave the correct configuration? Why?
                                    \nAnswer:
                                    \nRavi gave the correct configuration because according to Aufbau principle after completion of 3p orbital electron may enter either 4s or 3d.
                                    \nTheir n + l values are given below.<\/p>\n\n\n\n\n\n
                                    Orbital<\/td>\nn + l Values<\/td>\n<\/tr>\n
                                    4s<\/td>\n4 + 0 = 4<\/td>\n<\/tr>\n
                                    3d<\/td>\n3 + 2 = 5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                    So 4s orbital has lower n + l value when compared with 3d orbital. So electron enters into 4s.<\/p>\n

                                    Question 33.
                                    \nGiven the valence electron configuration of an element is 4s\u00b9. Then what are its quantum number values. Which element does it represent?
                                    \nAnswer:
                                    \nGiven valence electronic configuration is 4s\u00b9. So n = 4 for ‘s’ sub shell l = 0 and if l is ‘O’ then ml<\/sub> is also zero. ms<\/sub> takes only two values that is +\u00bd or -\u00bd for convenience we can take ms<\/sub> as +\u00bd.
                                    \n\u2234 The quantum number values are like this
                                    \n\"AP
                                    \nThe element is potassium.<\/p>\n

                                    Question 34.
                                    \nThe atomic number of an element is 17, then calculate the total number of electrons present in its s and p orbitals.
                                    \nAnswer:
                                    \nThe element with atomic number 17 is chlorine.
                                    \nIts electronic configuration is 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p5<\/sup>.
                                    \nSo, the total number of electrons present in s orbitals = 2 + 2 + 2 = 6.
                                    \nThe total number of electrons present in p orbitals = 6 + 5 = 11.<\/p>\n

                                    \"AP<\/p>\n

                                    Question 35.
                                    \nBased on Aufbau’s principle, in which of the three 4d, 5p and 5s orbitals the electrons will be filled first? Why?
                                    \nAnswer:
                                    \nAccording to Aufbau’s principle, the electron enters the orbital having lower n + l value. If both orbitals have same n + l values, electron enters the orbital with lower ‘n’ value.<\/p>\n\n\n\n\n\n\n
                                    Oprbital<\/td>\nn + l value<\/td>\n<\/tr>\n
                                    4d<\/td>\n4 + 3 = 7<\/td>\n<\/tr>\n
                                    5p<\/td>\n5 + 1 = 6<\/td>\n<\/tr>\n
                                    5s<\/td>\n5 + 0 = 5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                    So, 3s has least n + l value. Therefore the electron enters 5s orbital first.<\/p>\n

                                    Question 36.
                                    \nFind the following.
                                    \n1) Number of orbitals present in M orbit.
                                    \nAnswer:
                                    \nNumber of orbitals present in an orbit = n\u00b2 For M orbit n = 3.
                                    \n\u2234 So the number of orbitals = 3\u00b2 = 9.<\/p>\n

                                    2) The maximum and minimum possible ml<\/sub> values for 4f orbital.
                                    \nAnswer:
                                    \nFor f orbital ‘l’ value is 3. If l is 3, then ml<\/sub> takes values from – 3 to + 3.
                                    \nSo the minimum value for ml<\/sub> is – 3 and maximum value is + 3.<\/p>\n

                                    3) The possible values of l if n = 4.
                                    \nAnswer:
                                    \nIf n = 4, then l take values from 0 to 3 i.e., 0, 1, 2, 3.<\/p>\n

                                    4) The maximum number of electrons that can be filled in ‘N’ energy level.
                                    \nAnswer:
                                    \nFor N orbit n = 4. The maximum number of electrons present in a shell = n\u00b2.
                                    \n\u2234 The maximum number of electrons filled in N shell = 4\u00b2 = 16.<\/p>\n

                                    Question 37.
                                    \nHow do the vibrating electric and magnetic fields around the charge become a wave that travel through space?
                                    \nAnswer:<\/p>\n

                                      \n
                                    • A vibrating electric charge creates a change in the electric field.<\/li>\n
                                    • The changing electric field creates a changing magnetic field.<\/li>\n
                                    • This process continues, with both the created fields being perpendicular to each other and at right angles to the direction of propagation of the wave.<\/li>\n<\/ul>\n

                                      \"AP<\/p>\n

                                      Question 38.
                                      \nWhat information do the quantum numbers provide?
                                      \nAnswer:
                                      \nThe quantum numbers describe the space around the nuclear where the electrons are found and also their energies.<\/p>\n

                                      Question 39.
                                      \nAn electron in an atom has the following set of four quantum numbers. Which orbital does it belong to?<\/p>\n\n\n\n\n
                                      n<\/td>\nl<\/td>\nml<\/sub><\/td>\nms<\/sub><\/td>\n<\/tr>\n
                                      3<\/td>\n0<\/td>\n0<\/td>\n+\u00bd<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                      Answer:
                                      \nThe quantum numbers of an atom is given below.<\/p>\n\n\n\n\n
                                      n<\/td>\nl<\/td>\nml<\/sub><\/td>\nms<\/sub><\/td>\n<\/tr>\n
                                      3<\/td>\n0<\/td>\n0<\/td>\n+\u00bd<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                      By using nlx<\/sup> method n = 3, if l = 0 then the sub-shell is s.
                                      \nSo the electron belongs to 3s.<\/p>\n

                                      Question 40.
                                      \nLook at the following table and answer the following questions.
                                      \n\"AP
                                      \na) What is the law that is voilated in the above table? State that law.
                                      \nb) Write the correct table using that law.
                                      \nAnswer:
                                      \na) The law violated is Pauli’s Exclusive Principle. Pauli’s law states that no two electrons of the same atom can have all the four quantum numbers same.
                                      \nb)
                                      \n\"AP<\/p>\n

                                      10th Class Chemistry 8th Lesson Structure of Atom 4 Marks Important Questions and Answers<\/h3>\n

                                      Question 1.
                                      \nDraw Moeller chart of filling order of atomic orbitals.
                                      \n(OR)
                                      \nDraw a diagram showing the increasing value of (n + l) of orbitals. (AP June 2017)
                                      \nAnswer:
                                      \n\"AP
                                      \nThe filling order of atomic orbitals (Moeller Chart)<\/p>\n

                                      Question 2.
                                      \nComplete the following table based on quantum numbers related to atomic orbitals and electron of an atom. (AP SA-I-2018-19)
                                      \n\"AP
                                      \nAnswer:
                                      \n\"AP<\/p>\n

                                      Question 3.
                                      \nBased on the information given in the table, answer the questions given below.
                                      \n\"AP
                                      \ni) For the 4th main shell, how many values are there for ml<\/sub>? What are they? (TS June 2016)
                                      \nAnswer:
                                      \n1) There are 16 m( values in the 4th main shell.
                                      \n2) They are<\/p>\n\n\n\n\n\n\n\n\n
                                      Orbital<\/td>\nml <\/sub>values<\/td>\nTotal<\/td>\n<\/tr>\n
                                      4s<\/td>\n0<\/td>\n1<\/td>\n<\/tr>\n
                                      4p<\/td>\n-1, 0, + 1<\/td>\n3<\/td>\n<\/tr>\n
                                      4d<\/td>\n-2, -1, 0, + 1, +2<\/td>\n5<\/td>\n<\/tr>\n
                                      4f<\/td>\n-3, -2, -1, 0, +1, +2, +3<\/td>\n7<\/td>\n<\/tr>\n
                                      Total<\/td>\n16<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                      ii) For sub-shell with n = 3, l = 1, write the m, values.
                                      \nAnswer:
                                      \nFor sub – shell with n = 3, l = 1 the m, values are -1, 0, 1.<\/p>\n

                                      iii) Write the principal quantum number value for ‘N’ shell. How many sub-shells are there in the main shell?
                                      \nAnswer:<\/p>\n

                                        \n
                                      1. The principal quantum number value for \u2018N\u2019 shell is 4.<\/li>\n
                                      2. The number of sub-shells is 4. They are 4s, 4p, 4d, 4f.<\/li>\n<\/ol>\n

                                        iv) In the above table ml<\/sub> and l values are given. Write a formula that gives the relationship between ml<\/sub> and l based on those values.
                                        \nAnswer:
                                        \nml<\/sub> (No. of values) = 2l + 1.<\/p>\n

                                        Question 4.
                                        \nObserve the information provided in the table about quantum numbers. Then answer the questions given below it. (TS June 2017)<\/p>\n\n\n\n\n\n\n\n\n\n
                                        n<\/td>\nl<\/td>\nml<\/sub><\/td>\n<\/tr>\n
                                        1<\/td>\n0<\/td>\n0<\/td>\n<\/tr>\n
                                        2<\/td>\n0<\/td>\n0<\/td>\n<\/tr>\n
                                        1<\/td>\n-1, 0, +1<\/td>\n<\/tr>\n
                                        3<\/td>\n0<\/td>\n0<\/td>\n<\/tr>\n
                                        1<\/td>\n-1, 0, +1<\/td>\n<\/tr>\n
                                        2<\/td>\n-2, -1, 0, +1, +2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                        i) Write the ‘l’ value and symbol of the spherical shaped sub-shell.
                                        \nii) How many values that \u2018ml<\/sub>‘ takes for 1 = 2? What are they?
                                        \niii) Write the symbols of the orbitals for l = 1 sub-shell.
                                        \niv) What is the shape of the sub-shell for l = 2? What is the maximum number of electrons that can occupy this sub-shell?
                                        \nAnswer:
                                        \ni) Spherical shaped sub-shell “l\u201d value is zero and symbol is \u2018s’.
                                        \nii) Number of m; values for 1 = 2 is 5, those are -2, -1, 0, 1, 2.
                                        \niii) Symbols of the orbitals for l = 1 sub-shell are px<\/sub>, py<\/sub>, pz<\/sub>.
                                        \niv) Shape of the subshell l = 2 is double dumbel.
                                        \nThe maximum number of electrons that can occupy in this sub-shell is 10.<\/p>\n

                                        Question 5.
                                        \nWrite postulates and limitations of Bohr Hydrogen atomic model. (TS June 2018)
                                        \nAnswer:
                                        \nPostulates :<\/p>\n

                                          \n
                                        1. Niels Bohr proposed that electrons in an atom occupy ‘stationary’ orbits of fixed energy at different distances from the nucleus.<\/li>\n
                                        2. When an electron jumps from a lower energy state (ground state) to higher energy state it absorbs energy or emits energy when such a jump occurs from a higher energy state.<\/li>\n
                                        3. The energies of an electron in an atom can have only certain values E1<\/sub>, E2<\/sub>, E5<\/sub>…. that is, the energy is quantized.<\/li>\n<\/ol>\n

                                          Limitations :<\/p>\n

                                            \n
                                          1. Bohr’s model failed to account for splitting of line spectra of hydrogen atom into liner lines.<\/li>\n
                                          2. Bohr theory could not explain the Zeeman and Stark effect.<\/li>\n<\/ol>\n

                                            \"AP<\/p>\n

                                            Question 6.
                                            \nExplain Bohr’s model of hydrogen atom and its limitations. (March 2019)
                                            \nAnswer:
                                            \nNiels Bohr proposed that,
                                            \na) electrons in an atom occupy stationary orbits of fixed energy (K, L, M, N,…) at different distances from the nucleus.<\/p>\n

                                            b) when an electron jumps from a lower energy state to higher energy state, it ab\u00acsorbs energy or emits energy when such a jump occurs from a higher energy state to lower energy state.<\/p>\n

                                            c) the energies of an electron in an atom can have only certain values E1<\/sub>, E2<\/sub>, E3<\/sub>, ……… i.e. the energy is quantized. The states corresponding to these energies are called stationary states and the possible values of the energy are called energy levels.<\/p>\n

                                            d) the angular momentum of electron is multiple integral of \\(\\frac{L}{2 \\pi}\\).
                                            \n\u2234 L = mvr = \\(\\frac{\\mathrm{nh}}{2 \\pi}\\)
                                            \nm = mass of electron ;
                                            \nv = velocity of electron ;
                                            \nr = radius of circular path;
                                            \nh = plank constant<\/p>\n

                                            Limitations :<\/p>\n

                                              \n
                                            1. Bohr’s model failed to account for splitting of line spectra (Zeeman effect).<\/li>\n
                                            2. This model failed to account for the atomic spectra of atoms of more than one electron.<\/li>\n
                                            3. Bohr theory was not explained the quantisation of angular momentum of an electron.<\/li>\n
                                            4. It was not explained the formation of chemical bonds.<\/li>\n<\/ol>\n

                                              Question 7.
                                              \nExplain four quantum numbers with an example. (AP SA-I; 2019-20)
                                              \nAnswer:
                                              \nEach electron iii an atom is described by a set of three numbers called Quantum numbers.<\/p>\n

                                              1) Principal quantum number (n) :
                                              \nIt is used to know the size and energy of the main shell The values of ‘n’ are 1, 2, 3 …..
                                              \nenergy of the shell, n = 1 < energy of the Shell n = 2.<\/p>\n

                                              2) Angular momentum of quantum number (l) :
                                              \nIt is used to know the shape of a particular sub shell.
                                              \nThe values of ‘l’ are 0, 1, 2, 3
                                              \nl = 0 = s orbital = spherical in shape
                                              \nl = 1 = p orbital = dumbel in shape
                                              \nl = 2 = d orbital = double dumbel Shape<\/p>\n

                                              3) i) Magnetic quantum number (ml<\/sub>) :
                                              \nIt is used to describe the orientation of the orbital in space relative to the other orbitals in the atom.
                                              \nThe values of mt are – ‘l’ to \u2019+l’ including zero,<\/p>\n

                                              ii) Spin quantum number (ms<\/sub>) :
                                              \nIt is used to know the orientation of the spins of electrons.
                                              \nThe values of ms are +\u00bd and – \u00bd.<\/p>\n

                                              Question 8.
                                              \nHow does Hund’s rule helps in writing electronic configuration of an atom? Explain with a suitable example. (TS June 2019)
                                              \nAnswer:
                                              \nHund’s rule :
                                              \nAccording to this rule electron pairing in orbitals starts only when all available empty orbitals of the same energy are singly occupied.<\/p>\n

                                              This Hund’s rule helps in writing of electronic configuration of an element.<\/p>\n

                                              Example :<\/p>\n

                                                \n
                                              1. The electronic configuration of carbon (C) atom (Z = 6) is 1s\u00b2 2s\u00b2 2p6<\/sup>.<\/li>\n
                                              2. The first four electrons go into the Is and 2s orbitals.<\/li>\n
                                              3. The next two electrons go into separate 2p orbitals, with both electrons having the same spin.
                                                \n\"AP<\/li>\n<\/ol>\n

                                                Another example :<\/p>\n

                                                  \n
                                                1. The electronic configuration of oxygen (8<\/sub>O) is 1s\u00b2 2s\u00b2 2p4<\/sup>.<\/li>\n
                                                2. The first four electrons go into the 1s, 2s orbitals.<\/li>\n
                                                3. The next four electrons go into 2p orbits as 2 in 2px<\/sub>, 1 in 2py<\/sub> and 1 in 2pz<\/sub> orbital.
                                                  \n\"AP<\/li>\n
                                                4. Here pairing of electron in 2px starts after filling of electron in each 2px<\/sub>, 2py<\/sub>, 2pz<\/sub> orbitals.<\/li>\n
                                                5. But electrons do not occupy like this
                                                  \n\"AP<\/li>\n<\/ol>\n

                                                  Question 9.
                                                  \nYour father asked you to go to the market and purchase an electric lamp. The shop-keeper displayed two lamps – one is violet and another is red. Which coloured lamp do you purchase to put in your bedroom? Support your choice of solution.
                                                  \nAnswer:
                                                  \nRed has highest wavelength and violet has lowest wavelength. We know that relationship between energy as follows.
                                                  \nE = hv = h\\(\\frac{c}{\\lambda}\\)<\/p>\n

                                                  h and c are remains constant.
                                                  \n\u2234 E \u221d \\(\\frac{1}{\\lambda}\\)<\/p>\n

                                                  Energy is inversely proportional to wavelength. Red coloured light has lower energy and least intensity. So red coloured lamp is preferable as bed light.<\/p>\n

                                                  \"AP<\/p>\n

                                                  Question 10.
                                                  \nHeisenberg contradicts Neils Bohr. Explain in what way he contradicts.
                                                  \nAnswer:<\/p>\n

                                                    \n
                                                  • According to Bohr, electrons revolve around nucleus in definite paths or orbits. So the exact position of the electron at various times will be known to us.<\/li>\n
                                                  • In order to explain Bohr’s postulate we have to know the velocity and exact position of electron.<\/li>\n
                                                  • In order to find the position of electron we have to take the help of suitable light to find the position. As the electrons are very small, light of very short wavelength is required for this task.<\/li>\n
                                                  • This short wavelength light interacts with the electron and disturbs the motion of the electron.<\/li>\n
                                                  • Hence, it is not possible to find the exact position and velocity of electron simultaneously. This was stated by Heisenberg which is called Heisenberg’s principle of uncertainty.<\/li>\n
                                                  • In this way Heisenberg contradicts Neils Bohr.<\/li>\n<\/ul>\n

                                                    Question 11.
                                                    \nExplain Bohr-Sommerfeld model of an atom. What is the merit of this model? What are its limitations?
                                                    \nAnswer:<\/p>\n

                                                      \n
                                                    • In an attempt to account for the structure of line spectra, Sommerfeld modified Bohr’s atomic model by adding elliptical orbits.<\/li>\n
                                                    • While retaining the first of Bohr’s circular orbit as such, he added one elliptical orbit to Bohr’s second orbit, two elliptical orbits to Bohr’s third orbit, etc.<\/li>\n
                                                    • Nucleus of the atom is one of the principal foci of these elliptical orbits because periodic motion under the influence of a central force will lead to elliptical orbits with the force situated at one of the foci.<\/li>\n<\/ul>\n

                                                      \"AP<\/p>\n

                                                      Merit:
                                                      \nBohr-Sommerfeld model is successful in accounting for the fine line structure of hydrogen atomic spectra.<\/p>\n

                                                      Limitations :<\/p>\n

                                                        \n
                                                      1. This model failed to account for the atomic spectra of atoms of more than one electron.<\/li>\n
                                                      2. It did not explain Zeeman and Stark effects.<\/li>\n<\/ol>\n

                                                        Question 12.
                                                        \nIn an atom the number of electrons in N-shell is equal to the number of electrons in K, L and M shells. Answer the following questions.
                                                        \ni) Which is the outermost shell?
                                                        \nAnswer:
                                                        \nThe outermost shell is p(n = 6).<\/p>\n

                                                        ii) How many electrons are there in its outermost shell?
                                                        \nAnswer:
                                                        \nTwo electrons are there in outermost shell.<\/p>\n

                                                        iii) What is the atomic number?
                                                        \nAnswer:
                                                        \nIts atomic number is 56.<\/p>\n

                                                        iv) Write the electronic configuration of the elements.
                                                        \nAnswer:
                                                        \nThe electronic configuration of element is
                                                        \n1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup> 4s\u00b2 3d10<\/sup> 4p6<\/sup> 5s\u00b2 4d10<\/sup> 5p6<\/sup> 6s\u00b2.<\/p>\n

                                                        \"AP<\/p>\n

                                                        Question 13.
                                                        \nExplain the following electron configurations by using nlx<\/sup> method.
                                                        \na) 2p\u00b9
                                                        \nb) 3d5<\/sup>
                                                        \nc) 4f9<\/sup>
                                                        \nd) 6s\u00b2
                                                        \nAnswer:
                                                        \nIn nlx<\/sup> method n is the principle quantum number and l is the angular momentum quantum number and x is number of electrons. Now let us explain the following configurations
                                                        \na) 2p\u00b9 – It indicates that there is one electron in ‘p’ sub-shell of second orbit or shell.
                                                        \nb) 3d5<\/sup> – It indicates that there are five electrons in ‘d’ sub-shell of third orbit or shell.
                                                        \nc) 4f9<\/sup> – It indicates that there are nine electrons in ‘f’ sub-shell of fourth orbit or shell.
                                                        \nd) 6s\u00b2 – It indicates that there are two electrons in ‘s’ sub-shell of sixth orbit or shell.<\/p>\n

                                                        Question 14.
                                                        \nIn an atom the number of electrons in L shell is equal to three times of K shell. Then answer the following.
                                                        \n1) Which is the outermost shell?
                                                        \n2) How many electrons are there in outermost shell?
                                                        \n3) What is the atomic number of element?
                                                        \n4) Write electronic configuration of element.
                                                        \n5) Write name of element.
                                                        \nGiven that the number of electrons in L shell is three times of K shell.
                                                        \nAnswer:
                                                        \nWe know that number of electrons in K shell is 2.
                                                        \nTherefore number of electrons in L shell = 3 \u00d7 2 = 6<\/p>\n

                                                          \n
                                                        1. So the outermost shell is L.<\/li>\n
                                                        2. The number of electrons in outermost shell is 6.<\/li>\n
                                                        3. The atomic number of element is 8.<\/li>\n
                                                        4. The electronic configuration of element is 1s\u00b2 2s\u00b2 2p4<\/sup>.<\/li>\n
                                                        5. The element is oxygen.<\/li>\n<\/ol>\n

                                                          Question 15.
                                                          \nWe know that the electron configuration of copper is [Ar] 4s\u00b9 3d10<\/sup>. Is it against to Aufbau principle or not. If so, why is the configuration violated?
                                                          \nAnswer:<\/p>\n

                                                            \n
                                                          • The atomic number of copper is 29. So its electron configuration should be [Ar] 4s\u00b2 3d4<\/sup>.<\/li>\n
                                                          • But if one electron from 4s orbital jumps into 3d orbital, then copper gets half filled ‘d’ orbitals which gives stability to the atom.<\/li>\n
                                                          • The energy difference between 4s and 3d is very less. So one electron can easily jump from 4s to 3d which gives half-filled 3d5<\/sup> configuration.<\/li>\n
                                                          • So, in order to get additional stability, Aufbau principle is violated i.e., electron enters the orbital of higher energy before the completion ortrital of lower energy.<\/li>\n<\/ul>\n

                                                            Question 16.
                                                            \nElectronic configurations of following elements are written wrongly. Correct those configurations with proper explanation.
                                                            \n\"AP
                                                            \nAnswer:
                                                            \n1) The electron configuration of oxygen is 1s\u00b2 2s\u00b2 2p4<\/sup> because the maximum number of electrons that can be filled in s orbital is 2 and so the extra electron should be entered in 2p.<\/p>\n

                                                            2) The correct electron configuration of nitrogen is
                                                            \n\"AP
                                                            \nThe reason is that the pairing of electrons does not take place until each degenerate orbital is filled with one electron each (Hund’s principle).<\/p>\n

                                                            3) The correct electronic configuration of scandium is 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup> 4s\u00b9 because after completion of 3p orbital electron enters in 4s because the energy of 4s orbital is less than 3d (Aufbau principle).<\/p>\n

                                                            4) The correct electronic configuration of chromium is 1s\u00b2 2s\u00b2 2p6<\/sup> 3s\u00b2 3p6<\/sup> 4s\u00b9 3d5<\/sup>. Because atoms having half filled or completely filled orbitals are more stable. So by transferring one electron from 4s to 3d the atom gets extra stability.<\/p>\n

                                                            Question 17.
                                                            \nHere is set of quantum numbers. Do they form correct values of quantum numbers or not. If not, give reason.
                                                            \n\"AP
                                                            \nThe values l, ml<\/sub>, ms<\/sub> are not correct values for given ‘n’.
                                                            \nAnswer:<\/p>\n

                                                              \n
                                                            • The maximum value for l is n – 1. If n = 3, then l takes values from 0 to 2. That is 0, 1, 2.<\/li>\n
                                                            • ml<\/sub> values depend on ‘l’. ml<\/sub> take values from – l to + l including zero. So, the possible values for m7 may be from – 2 to + 2.<\/li>\n
                                                            • Spin quantum number has only two values, i.e. and –\\(\\frac{1}{2}\\) and \\(\\frac{1}{2}\\). So \\(\\frac{1}{4}\\) value is not possible.<\/li>\n<\/ul>\n

                                                              \"AP<\/p>\n

                                                              Question 18.
                                                              \nAnswer the following questions.
                                                              \na) If n = 4, then what energy level does it represent?
                                                              \nAnswer:
                                                              \nIf n = 4, then it represents N energy level.<\/p>\n

                                                              b) If n = 5, then what is the maximum value for l and why?
                                                              \nAnswer:
                                                              \nIf n = 5, then the maximum value of l for 4 because the maximum value for l is n- 1.<\/p>\n

                                                              c) If l = 3, then what are the maximum possible values for ml<\/sub>?
                                                              \nAnswer:
                                                              \nGiven l = 3.
                                                              \nThen possible values for ml<\/sub> is 2l + 1.
                                                              \n\u2234 Maximum possible values = 2(3) +1 = 7<\/p>\n

                                                              d) What is the number of electrons present in M energy level?
                                                              \nAnswer:
                                                              \nFor M energy level n = 3.
                                                              \nThe maximum number of electrons in an orbit = 2n\u00b2 = 2 \u00d7 3\u00b2 = 2 \u00d7 9 = 18<\/p>\n

                                                              Question 19.
                                                              \nDraw the shapes of s, p and d orbitals.
                                                              \nAnswer:
                                                              \ns – orbital (Spherical) :
                                                              \n\"AP
                                                              \np – orbital (Dumbell) :
                                                              \n\"AP
                                                              \nAll P:
                                                              \n\"AP
                                                              \nd – orbital (Double Dumbell):
                                                              \n\"AP<\/p>\n

                                                              Question 20.
                                                              \nDraw electromagnetic wave and label its parts.
                                                              \nAnswer:
                                                              \n\"AP<\/p>\n

                                                              Question 21.
                                                              \nDraw the diagram of electromagnetic spectrum.
                                                              \nAnswer:
                                                              \n\"AP<\/p>\n","protected":false},"excerpt":{"rendered":"

                                                              AP State Board Syllabus AP SSC 10th Class Physical Science Important Questions Chapter 8 Structure of Atom. AP State Syllabus SSC 10th Class Chemistry Important Questions 8th Structure of Atom 10th Class Chemistry 8th Lesson Structure of Atom 1 Mark Important Questions and Answers Question 1. Write the electronic configuration of chromium. (AP June 2016) …<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[2],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/posts\/3798"}],"collection":[{"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/comments?post=3798"}],"version-history":[{"count":1,"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/posts\/3798\/revisions"}],"predecessor-version":[{"id":36439,"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/posts\/3798\/revisions\/36439"}],"wp:attachment":[{"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/media?parent=3798"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/categories?post=3798"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/apboardsolutions.guru\/wp-json\/wp\/v2\/tags?post=3798"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}