Carbon Cycle and Atmospheric Composition

The video tutorial explains matter cycles, focusing on the carbon cycle. It covers the composition of Earth's atmosphere, the concept of Earth as a closed system, and how carbon circulates through respiration, combustion, and decomposition. The tutorial also discusses how carbon dioxide is consumed by plants and animals, and the role of oceans in the carbon cycle. The video concludes with a summary of the carbon cycle's impact on maintaining atmospheric balance.

What percentage of Earth's atmosphere is made up of nitrogen?

• 78.08%

• 20.95%

• 1%

• 99%

Why is Earth's atmosphere considered a closed system?

• Because it is constantly changing

• Because nothing can enter or leave it under normal circumstances

• Because it allows free exchange of gases

• Because it is open to space

Which of the following is NOT a source of carbon dioxide entering the atmosphere?

• Decomposition

• Combustion

• Photosynthesis

• Respiration

How do plants use carbon dioxide from the atmosphere?

• For respiration

• To release oxygen

• To produce carbohydrates through photosynthesis

• To decompose organic matter

What happens to carbon in the bodies of dead plants and animals?

• It becomes part of the soil

• It is converted into oxygen

• It is permanently removed from the cycle

• It is returned to the atmosphere as carbon dioxide

In aquatic environments, how is carbon used by marine life?

• To decompose organic matter

• To produce oxygen

• To form calcium carbonate for shells

• To create fossil fuels

What is the role of limestone in the carbon cycle?

• It is used by plants for photosynthesis

• It is a source of fossil fuels

• It releases carbon dioxide back into the atmosphere upon weathering

• It absorbs carbon dioxide from the atmosphere

How does chemical weathering contribute to the carbon cycle?

• By forming new rocks

• By dissolving rocks and releasing carbon

• By absorbing carbon dioxide

• By creating fossil fuels

What percentage of the atmosphere is carbon dioxide?

• 1%

• 0.03%

• 78.08%

• 20.95%

Which process is responsible for returning carbon dioxide to the atmosphere from marine life?

• Photosynthesis

• Respiration

• Decomposition

• Combustion