Science 5

41.

What is laughing gas?

A. Nitrous Oxide

B. Carbon monoxide

C. Sulphur dioxide

D. Hydrogen peroxide

Answer: Option A

Explanation:

42.

Actinides are the elements with atomic numbers from

A. 97 to 104

B. 101 to 115

C. 89 to 103

D. 36 from 43

Answer: Option C

43.

The two elements that are frequently used for making transistors are

A. boron and aluminium

B. silicon and germanium

C. iridium and tungsten

D. niobium and columbium

Answer: Option B

Explanation:

44.

The filament of an electric bulb is made of

A. tungsten

B. nichrome

C. graphite

D. iron

Answer: Option A

45.

Diamond is an allotropic form of

A. germanium

B. carbon

C. silicon

D. sulphur

Answer: Option B

46.

In fireworks, the green flame is produced because of

A. sodium

B. barium

C. mercury

D. potassium

Answer: Option B

Explanation:

47.

Permanent hardness of water can be removed by adding

A. chlorine

B. washing soda

C. potassium permanganate

D. bleaching powder

Answer: Option B

48.

Marsh gas is

A. nitrogen

B. ethane

C. methane

D. hydrogen

Answer: Option C

Explanation:

49.

LPG consists of mainly

A. methane, ethane and hexane

B. ethane, hexane and nonane

C. methane, hexane and nonane

D. methane, butane and propane

Answer: Option D

Explanation:

50.

Air is a/an

A. compound

B. element

C. electrolyte

D. mixture

Answer: Option D

You Can Also Visit My Previous Post :

• Science 10
• Science 9
• Science 8