Atomic Structure PYQs Set 6 (PDF)

Set 6 of 12 · Questions 151-180 of 359

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Mere Teacher · Previous Year Questions NEET Chemistry · Atomic Structure · Set 6 (Q151-180)
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151. $The position of both, an electron and a helium atom are known within 1.0 nm. Further the momentum of the electron is known within 5.0 \times 1 0^{- 26} kg m s^{- 1} . The minimum uncertainty in the measurement of the momentum of the helium atom is$ (1) $8. 0 \times 1 0^{- 26} kg m s^{- 1}$ (2) $80 kg m s^{- 1}$ (3) $50 kg m s^{- 1}$ (4) $5. 0 \times 1 0^{- 26} kg m s^{- 1}$ 152. $Calculate the wave number of the photon emitted during transition from the orbit of n = 2 to n = 1 in hydrogen atom (R_{H} = 109677 cm^{- 1}) .$ (1) $27419.3 cm^{- 1}$ (2) $12064.5 cm^{- 1}$ (3) $109677.0 cm^{- 1}$ (4) $82257.8 cm^{- 1}$ 153. $Which of the following set of quantum numbers represents the highest energy of an atom ?$ (1) $n = 3, l = 0, m = 0, s = + \frac{1}{2}$ (2) $n = 3, l = 1, m =1, s = + \frac{1}{2}$ (3) $n = 3, l = 2, m = 1, s = + \frac{1}{2}$ (4) $n = 4, l = 0, m = 0, s = + \frac{1}{2}$ 154. $Match the following. List I A. Chadwick B. Rutherford C. Moseley D. J. J. Thomson List II 1.Cathode rays 2 X-rays spectra 3. Discovery of neutrons 4. Nuclear atom model A B C D$ (1) $4 1 2 3$ (2) $3 2 4 1$ (3) $3 2 1 4$ (4) $3 4 2 1$ 155. $If the principal quantum number n = 6, the correct sequence of filling of electrons will be :$ (1) $ns\tonp\to(n - 1)d\to(n - 2)f$ (2) $ns\to(n - 1)d\to(n - 2)f\tonp$ (3) $ns\to(n - 2)f\tonp\to(n - 1)d$ (4) $ns\to(n - 2)f\to(n - 1)d\tonp$ 156. $If the radius and energy of the second Bohr orbit of hydrogen atom is r_{2} and E_{2}, respectively. The radius and energy of the third Bohr orbit will be______ respectively.$ (1) $\frac{4}{9} r_{2}, \frac{9}{4} E_{2}$ (2) $\frac{4}{9} r_{2}, \frac{4}{9} E_{2}$ (3) $\frac{9}{4} r_{2}, \frac{4}{9} E_{2}$ (4) $\frac{9}{4} r_{2}, \frac{9}{4} E_{2}$ 157. $Heat treatment of muscular pain involves radiation of wavelength of about 900 nm. Which spectral line of H atom is suitable for this? Given : Rydberg constant R_{H} = 10^{5} cm^{- 1}, h = 6.6 \times 10^{- 34} J s, c = 3 \times 10^{8} m / s)$ (1) $Balmer series, \infty \to 2$ (2) $Lyman series, \infty \to 1$ (3) $Paschen series, \infty \to 3$ (4) $Paschen series, 5 \to 3$ 158. $In which of the following, orbitals are correctly arranged in the increasing order of their energies?$ (1) $4 f < 5 p < 5 d < 6 s$ (2) $5 p < 4 f < 6 s < 5 d$ (3) $5 p < 6 s < 4 f < 5 d$ (4) $5 p < 5 d < 4 f < 6 s$ 159. $The de-Broglie wavelength of a particle of mass 6.63 g moving with a velocity of 100 m s^{-1} is :$ (1) $1 0^{-33} m$ (2) $1 0^{-35} m$ (3) $1 0^{-31} m$ (4) $1 0^{-25} m$ 160. $If the kinetic energy of a particle is reduced to half, de-Broglie wavelength becomes$ (1) $2 times$ (2) $\frac{1}{2} times$ (3) $4 times$ (4) $2 times$ 161. $What is the work function of the metal if the light of wavelength 4000Å generates photoelectrons of velocity 6 \times 10^{5} m s^{- 1} from it? (Mass of electron = 9 \times 10^{- 31} kg Velocity of light = 3 \times 10^{8} m s^{- 1} Planck’s constant = 6.626 \times 10^{- 34} Js Charge of electron = 1.6 \times 10^{- 19} Je V^{- 1})$ (1) $0.9 eV$ (2) $3.1eV$ (3) $2.1 eV$ (4) $4.0 eV$ 162. $The number of protons, neutrons and electrons in the ion_{16}^{32} S^{2 -} respectively are$ (1) $16, 18, 16$ (2) $18, 16, 16$ (3) $16, 16, 18$ (4) $16, 16, 16$ 163. $The frequency of radiation emitted when the electron falls from n = 4 to n = 1 in a hydrogen atom will be (Given ionization energy of H = 2.18 \times 1 0^{- 18} J a t o m^{- 1} and h = 6.625 \times 1 0^{- 34} J s)$ (1) $1. 54 \times 1 0^{15} s^{- 1}$ (2) $1. 03 \times 1 0^{15} s^{- 1}$ (3) $3. 08 \times 1 0^{15} s^{- 1}$ (4) $2. 00 \times 1 0^{15} s^{- 1}$ 164. $The ground state of energy of hydrogen atom is - 13.6 eV. The energy of second excited state of H e^{+} ion in eV is :$ (1) $- 54.4$ (2) $- 3.4$ (3) $- 6.04$ (4) $- 27.2$ 165. $For the Balmer series in the spectrum of H -atom, v = R_{H} ((1/ n 1^{2}) - (1/ n 2^{2})) The correct statements among (A) to (D) are: (A) The integer n_{1} = 2 (B) The ionization energy of hydrogen can be calculated from the wave number of these lines.(C) The lines of longest wavelength correspond to n_{2} = 3 .(D) As wavelength decreases, the lines of the series converge.$ (1) $B, C, D$ (2) $A, B, D$ (3) $A, C, D$ (4) $A, B, C$ 166. $4 d, 5 p, 5 f and 6p orbitals are arranged in the order of decreasing energy. The correct option is$ (1) $5 f > 6 p > 5 p > 4 d$ (2) $6 p > 5 f > 5 p > 4 d$ (3) $6 p > 5 f > 4 d > 5 p$ (4) $5 f > 6 p > 4 d > 5 p$ 167. $Which of the following statements in relation to the hydrogen atom is correct?$ (1) $3s, 3p and 3d orbitals all have the same energy$ (2) $3s and 3p orbitals are of lower energy than 3d orbital$ (3) $3p orbital is lower in energy than 3d orbital$ (4) $3s orbital is lower in energy than 3p orbital$ 168. $The radius of the first orbit of Li^{2 +} is x Å . The radius of the third orbit of He^{+} (in Å) is$ (1) $\frac{18}{2} x$ (2) $\frac{18}{3} x$ (3) $\frac{27}{4} x$ (4) $\frac{27}{2} x$ 169. $The shortest wavelength of H atom in the Lyman series is λ_{1} The longest wavelength in the Balmar series of He^{+} is$ (1) $\frac{5 λ _{1}}{9}$ (2) $\frac{36 λ _{1}}{5}$ (3) $\frac{27 λ _{1}}{5}$ (4) $\frac{9 λ _{1}}{5}$ 170. $The energy of an electron in the first Bohr orbit of hydrogen atom is -2.18 x 1 0^{- 18} J Its energy in the third Bohr orbit is________.$ (1) $\frac{1}{9} th of the value$ (2) $\frac{1}{27} of this value$ (3) $Three times of this value$ (4) $One third of this value$ 171. $Two series of spectral lines of atomic hydrogen which do not belong to infrared spectral region are$ (1) $Lyman and Paschen$ (2) $Balmer and Brackett$ (3) $Pfund and Lyman$ (4) $Lyman and Balmer$ 172. $The wavelength of spectral line obtained in the spectrum of Li^{2 +} ion, when the transition takes place between two levels whose sum is 4 and difference is 2 , is$ (1) $1.14 \times 10^{- 7} cm$ (2) $1.14 \times 10^{- 6} cm$ (3) $2.28 \times 10^{- 7} cm$ (4) $2.28 \times 10^{- 6} cm$ 173. $If the radius of electron orbit in the excited state of hydrogen atom is 476.1 pm, the energy of electron in that excited state in J is (Radius and energy of electron in the first orbit of hydrogen atom are 52.9 pm and - 2.18 \times 10^{- 18} J respectively)$ (1) $- 2.42 \times 10^{- 18}$ (2) $- 19.62 \times 10^{- 18}$ (3) $- 2.42 \times 10^{- 19}$ (4) $- 6.05 \times 10^{- 19}$ 174. $Calculate radius of third orbit of He^{+} .$ (1) $52.9 pm$ (2) $105.8 pm$ (3) $238.1 pm$ (4) $423.2 pm$ 175. $The quantum number of four electrons are given below: I. n = 4, l = 2, m_{l} = - 2, m_{s} = - \frac{1}{2} II. n = 3, l = 2, m_{l} = 1, m_{s} = + \frac{1}{2} III. n = 4, l = 1, m_{l} = 0, m_{s} = + \frac{1}{2} IV. n = 3, l = 1, m_{l} = 1, m_{s} = - \frac{1}{2} The correct order of their increasing energies will be:$ (1) $IV<III<II<I$ (2) $I<II<III<IV$ (3) $IV<II<III<I$ (4) $I<III<II<IV$ 176. $Given below are two statements: Statement (I): For a given shell, the total number of allowed orbitals is given by n^{2} . Statement (II): For any subshell, the spatial orientation of the orbitals is given by - l to + l values including zero. choose the correct answer from the options given below:$ (1) $Both Statement I and Statement II are false$ (2) $Statement I is true but Statement II is false$ (3) $Both Statement I and Statement II are true$ (4) $Statement I is false but Statement II is true$ 177. $The de Broglie wavelength of an electron in the 4^{th} Bohr orbit is$ (1) $4 π a_{0}$ (2) $2 π a_{0}$ (3) $8 π a_{0}$ (4) $6 π a_{0}$ 178. $Which of the following statements is correct about photoelectric effect? 1.The number of electrons ejected from metal surface is inversely proportional to intensity of light. 2.Below threshold frequency, photoelectric effect can be observed. 3.At higher frequency than threshold frequency, the ejected electrons have certain kinetic energy. 4.At higher frequency than threshold frequency, the electron is still on the metal surface.$ (1) $1$ (2) $2$ (3) $3$ (4) $4$ 179. $The total number of orbitals associated with the principal quantum number 5 is:$ (1) $5$ (2) $20$ (3) $25$ (4) $10$ 180. $In hydrogen atom, the minimum energy required to excite an electron from 2^{nd} orbit to the 3^{rd} orbit is$ (1) $2.2 eV$ (2) $2.7 eV$ (3) $1.9 eV$ (4) $7 eV$