Atomic Structure | First Year Chemistry Past Paper MCQs | mosaicbro.com

Atomic Structure | First Year Chemistry Past Paper MCQs

7 of 44 questions (Page 6 of 7)

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36 Mass of one mole of electron is:
Correct Answer: A
Explanation: Mass of 1 mole e⁻ = 9.109 × 10⁻³¹ kg × 6.022 × 10²³ ≈ 0.55 mg.
37 If an electron is free from the attraction of nucleus, then its energy is:
Correct Answer: C
Explanation: Zero energy is defined as complete separation from the nucleus (n=∞ in Bohr model).
38 In discharge tube experiment, the pressure of gas was maintained at:
Correct Answer: C
Explanation: Low pressure (~0.01 torr) allows electron beams to travel without collisions.
39 Splitting of spectral lines when atoms are subjected to strong magnetic field is called:
Correct Answer: A
Explanation: Zeeman effect: magnetic fields split atomic energy levels.
40 Which one of the following series lies in ultraviolet region?
Correct Answer: A
Explanation: Lyman series (n→1) emits UV radiation.
41 The shape of 'P' orbitals is:
Correct Answer: C
Explanation: p-orbitals have a dumbbell shape with two lobes.
42 Value of Rydberg's constant is:
Correct Answer: C
Explanation: Rydberg constant (R_H) = 1.097 × 10⁷ m⁻¹ for hydrogen.
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