Science 2

11.

Bromine is a

A. black solid

B. red liquid

C. colourless gas

D. highly inflammable gas

Answer: Option B

12.

The hardest substance available on earth is

A. Gold

B. Iron

C. Diamond

D. Platinum

Answer: Option C

13.

The variety of coal in which the deposit contains recognisable traces of the original plant material is

A. bitumen

B. anthracite

C. lignite

D. peat

Answer: Option D

Explanation:

14.

Tetraethyl lead is used as

A. pain killer

B. fire extinguisher

C. mosquito repellent

D. petrol additive

Answer: Option D

15.

Which of the following is used as a lubricant?

A. Graphite

B. Silica

C. Iron Oxide

D. Diamond

Answer: Option A

16.

The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is

A. Argon

B. Xenon

C. Helium

D. Krypton

Answer: Option C

17.

The gases used in different types of welding would include

A. oxygen and hydrogen

B. oxygen, hydrogen, acetylene and nitrogen

C. oxygen, acetylene and argon

D. oxygen and acetylene

Answer: Option D

18.

The property of a substance to absorb moisture from the air on exposure is called

A. osmosis

B. deliquescence

C. efflorescence

D. desiccation

Answer: Option B

19.

In which of the following activities silicon carbide is used?

A. Making cement and glass

B. Disinfecting water of ponds

C. cutting very hard substances

D. Making casts for statues

Answer: Option C

20.

The average salinity of sea water is

A. 3%

B. 3.5%

C. 2.5%

D. 2%

Answer: Option B

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