Title Chapter test-2 (Atomic structure).doc ✅

1 Marking Scheme: (i) Each question is allotted 4 (four) marks for each correct response. (ii) ¼ (one fourth) marks will be deducted for indicating incorrect response of each question. No deduction from the total score will be made if no response is indicated for an item in the answer sheet. –––––––––––––––––––––––––––––––––––––––––––––––– Q.1 The atomic number of an element is equal to the – (A) number of neutrons (B) electrical charge of the nucleus (C) weight of the nucleus (D) atomic weight divided by two Q.2 Wave nature of electrons was demonstrated by – (A) Schrodinger (B) de-Broglie (C) Davission and Germer (D) Heisenberg Q.3 What is the wave number for 4th line in Balmer series of hydrogen spectrum ? (R = 109677 cm–1) (A) 24630 cm–1 (B) 24360 cm–1 (C) 24730 cm–1 (D) 24372 cm–1 Q.4 19K40 and 20Ca40 are known as – (A) isotopes (B) isobars (C) isotones (D) isodiaphers Q.5 What is the wavelength (in metre) of a particle of mass 6.62 × 10–29g moving with a velocity of 103 m/s – (A) 6.62 × 10–4 (B) 6.62 × 10–3 (C) 10–5 (D) 105 Q.6 What are the values of n1 and n2 respectively for H line in the Lyman series of hydrogen atomic spectrum ? (A) 3 and 5 (B) 2 and 3 (C) 1 and 3 (D) 2 and 4 Q.7 Electronic configuration of hydride ion is – (A) 1s0 (B) 1s1 (C) 1s2 (D) 1s1 2s1 Q.8 Which one of the following has unit positive charge and 1u mass – (A) Electron (B) Neutron (C) Proton (D) None of these Q.9 Which is not in accordance to Aufbau principle ? (A) (B) 2s2p 2s2p (C) (D) 2s2p 2s2p Q.10 What is the electronic configuration of Mn2+ ? (A) [Ne] 3d5 4s0 (B) [Ar] 3d5 4s2 (C) [Ar] 3d5 4s0 (D) [Ne] 3d5 4s2 Q.11 The radius of hydrogen atom is 0.53Å. The radius of 3Li2+ is of – (A) 1.27 Å (B) 0.17 Å (C) 0.57 Å (D) 0.99 Å Q.12 If the energy of a photon is given as : 3.03 × 10–19 J, then wavelength  of the photon is – (A) 6.56nm (B) 65.6nm (C) 656nm (D) 0.656nm Q.13 In hydrogen atom, energy of first excited state is – 3.4eV. Find out KE of the same orbit of Hydrogen atom – (A) + 3.4 eV (B) + 6.8 eV (C) – 13.6 eV (D) + 13..6 eV Q.14 The value of Planck’s constant is 6.63 × 10–34 Js. The velocity of light is 3.0 × 108 m/s. Which value is closest to the wavelength in nanometers of a quantum of light with frequency of 8 × 1015 s–1 ? (A) 3 × 107 (B) 2 × 10–25 (C) 5 × 10–18 (D) 4 × 101 Q.15 An electron collides with a hydrogen atom in its ground state and excited it to a state of n = 3. How much energy was given to the hydrogen atom in this inelastic collision – (A) 12.08 eV (B) 6.12 eV (C) 15.14 eV (D) 18.21 eV Q.16 Given : The mass of electron is 9.11 × 10–31 kg , Planck constant is 6.626 × 10–34 Js, the uncertainty involved in the measurement of velocity within a distance of 0.1Å is – (A) 5.79 × 107 m/s (B) 5.79 × 108 m/s (C) 5.79 × 105 m/s (D) 5.79 × 106 m/s Q.17 The orientation of an atomic orbital is governed by – (A) Spin quantum number (B) Magnetic quantum number (C) Principal quantum number (D) Azimuthal quantum number For Q.18-Q.20 Werner Heisenberg considered the limits of how precisely we can measure the properties of an electron or other microscopic particle. He determined that there is a fundamental limit to how closely we can measure both position and momentum. The more accurately we measure the momentum of a particle, the less accurately we can determine its position. The converse is also true. This is summed up in what we now call the Heisenberg uncertainty principle. The equation is h x.(mv) 4  The uncertainty in the position or in the momentum of a macroscopic object like a baseball is too small to observe. However, the mass of microscopic object such as an electron is small enough for the uncertainty to be relatively large and significant. Q.18 If the uncertainties in position and momentum are equal, the uncertainty in the velocity is – (A) h  (B) h 2 (C) 1h 2m (D) None of these JEE MAINCHAPTER TEST Subject : Chemistry Topic : Atomic structure M.M. : 100