set 3 MCQ Questions & Answers Detailed Explanation

Question : 1

In an atom, the order of filling up of the orbitals is governed by

a) Heisenberg’s uncertainty principle

b) Hund’s rule

c) Aufbau’s principle

d) Pauli’s exclusion principle

Question : 2

The atomic weights are expressed in terms of atomic mass unit. Which one of the following is used as a standard?

a) ¹⁶O₈

b) ¹²C₆

c) ¹H₁

d) ³⁵Cl₁₇

Question : 3

Which of the following describes an isotope with a mass number of 99 that contains 56 neutrons in its nucleus ?

a) $↖43↙56{Ba}$

b) $↖99↙43{Tc}$

c) $↖99↙56{Ba}$

d) $↖56↙43{Tc}$

Question : 4

What is the number of water molecules present in a tiny drop of water ( volume 0.0018 ml ) at room temperature?

a) 6.023 × 10¹⁹

b) 4.184 × 10¹⁸

c) 4.84 × 10¹⁷

d) 6.023 × 10²³

Question : 5

One gram of which of the following contains largest number of oxygen atoms?

a) O₂

b) O₃

c) O

d) All contains same

Question : 6

Protons and neutrons are bound in a nucleus by the

a) long range ‘electromagnetic interaction’

b) short range ‘strong interaction’

c) short range ‘weak interaction’

d) long range ‘gravitational interaction’