Air Basics: 15 MCQs with answers

A · Nitrogen

Nitrogen constitutes about 78% of the atmosphere, making it the most abundant gas.

A · 21%

Oxygen makes up about 21% of the atmosphere, essential for respiration.

A · Carbon dioxide

Plants take in carbon dioxide from the air for photosynthesis.

D · Burning of fossil fuels

Burning fossil fuels releases pollutants like carbon monoxide, sulfur dioxide, and particulate matter.

D · Air pressure

Air pressure is the force exerted by the weight of air molecules.

D · Transpiration

Transpiration is the loss of water vapor from plant leaves, contributing to humidity.

C · Troposphere

The troposphere is the lowest layer where weather occurs.

B · False

Air is a mixture of gases, not a pure substance.

B · False

Carbon dioxide is about 0.04%, while oxygen is about 21%.

A · Argon

Argon is a noble gas present in about 0.93% of the atmosphere.

B · The Sun

Solar energy heats the Earth unevenly, causing air movement and weather patterns.

A · Stratosphere

The ozone layer is located in the stratosphere, protecting life from UV radiation.

D · Carbon dioxide

Carbon dioxide traps heat in the atmosphere, contributing to global warming.

C · Carbon monoxide

Carbon monoxide is emitted directly from sources like vehicles and is a primary pollutant.

D · Ozone and particulate matter

Smog is a mixture of pollutants, primarily ground-level ozone and fine particles.