Evolution of Earth's atmosphere | Starter Quiz | Oak National Academy

Earth's atmosphere comprises approximately 21% of which gas?

Answer explanation

Earth's atmosphere is composed of 21% oxygen.

What is the percentage of carbon dioxide in Earth's atmosphere?

• 78%

• 21%

• 1%

• 0.04%

Answer explanation

The percentage of carbon dioxide in Earth's atmosphere is 0.04%

How old is Earth thought to be?

• 4 million years

• 4.5 billion years

• 2 million years

• 200 billion years

Answer explanation

Earth is believed to be 4.5 billion years old.

The atmosphere on Earth has been in roughly the same proportions for how many million years?

Answer explanation

The atmosphere on Earth has been in the same proportions for the last 200 million years.

What name is given to the layer of gas that surrounds a planet?

Answer explanation

The atmosphere is the layer of gas that surrounds a planet.

What is the name of this process?

• respiration

• combustion

• photosynthesis

• sedimentation

Answer explanation

Photosynthesis is the process by which plants convert water and carbon dioxide into glucose and oxygen.