set 3 MCQ Questions & Answers Detailed Explanation

Question : 1

Naturally occuring substances from which a metal can be profitably (or economically) extracted are called?

a) Gangue

b) Minerals

c) Ores

d) Salts

Question : 2

Consider the following statements: Nitrogen is an essential constituent of

1. Soils
2. Animals
3. Plants

a) (i) and (ii) only

b) (iii) only

c) (i) and (iii) only

d) (i), (ii) and (iii)

Question : 3

Why is nitrogen molecule chemically less active?

a) It has high electronegativity

b) It has high dissociation energy

c) It has small atomic radius

d) It has stable electronic configuration

Question : 4

Which one among the following does not have an allotrope?

a) Sulphur

b) Nitrogen

c) Oxygen

d) Carbon

Question : 5

The most commonly used substance in fluorescent tubes are

a) Sodium Vapour and Neon

b) Mercury Vapour and Argon

c) Sodium Oxide and Argon

d) Mercuric Oxide and Neon

Question : 6

Yellow colour of usual nitric acid is due to the presence of which one of the following?

a) NO

b) N₂₅

c) N₂O

d) NO₂