set 2 MCQ Questions & Answers Detailed Explanation

Question : 1

$H_2O$ is liquid and $H_2S$ is a gas because

a) atomic radius of oxygen is less than that of sulphur.

b) oxygen is less electronegative than sulphur.

c) oxygen forms stronger hydrogen bonding than sulphur.

d) atomic radius of oxygen is greater than that of sulphur.

Question : 2

Match List-I with List-II :

a) 4 1 2 3

b) 3 2 1 4

c) 2 3 1 4

d) 3 1 2 4

Question : 3

Approximately, how many different chemical elements exist in the Earth?

a) 300

b) 200

c) 250

d) 100

Question : 4

When iron is left exposed in open air, it gets rusted. Which constituent(s) of air is /are responsible for rusting iron?

1. Oxygen gas present in air
2. Moisture present in air
3. Carbon dioxide gas present in air

a) 1 and 2

b) 2 only

c) 1 only

d) 2 and 3

Question : 5

The element found maximum in the soil layer is

a) Oxygen

b) Manganese

c) Nitrogen

d) Silicon

Question : 6

Consider the following statements with reference to the periodic table of chemical elements.

1. Ionization potential gradually decreases along a period.
2. In a group of elements, electron affinity decreases as the atomic weight increases.
3. In a given period, electronegativity decreases as the atomic number increases.

a) Only 1

b) 1 and 3

c) Only 2

d) 2 and 3