Layers and Composition of the Atmosphere

Which gas makes up the greatest percentage of Earth's atmosphere?

• Argon

• Nitrogen

• Nitrous oxide

• Carbon dioxide

This circle graph shows the percentage of different gases in Earth's atmosphere. Which gas is represented by Gas #1?

• Carbon dioxide

• Hydrogen

• Nitrogen

• Oxygen

Earth's atmosphere is mainly composed of which gases?

• hydrogen, helium, oxygen, and argon

• nitrogen, oxygen, argon, and carbon dioxide

• nitrogen, hydrogen, argon, and carbon dioxide

• helium, hydrogen, oxygen, and carbon dioxide

Which element makes up MOST of the air we breathe?

• Carbon

• Nitrogen

• Oxygen

• Argon

Which element makes up the LEAST amount of the air breathe?

• Carbon

• Nitrogen

• Oxygen

• Argon

A certain element makes up 78 percent of Earth's atmosphere. It interacts with other elements to provide many of the nutrients needed in an ecosystem. What is the name of this element?

• Nitrogen

• Oxygen

• Carbon

• Chlorine

In the nitrogen cycle, where is nitrogen found as an element?

• in plants

• in rocks

• in the air

• in animals

Which gas makes up the majority of the Earth's atmosphere?

• Argon

• Oxygen

• Nitrogen

• Carbon dioxide

The table indicates the percentage of some gases in the atmosphere of Mars. Which gas present in the atmosphere of Mars is the primary gas found in the atmosphere of Earth?

• Carbon dioxide

• Nitrogen

• Argon

• Methane

A scientist compared the atmospheric composition of a newly discovered planet to the atmosphere of Earth. Which conclusion about the unknown planet can be made by using the information provided?

• It is not suitable for animals.

• It will sustain a small human population.

• It has enough oxygen for small mammals.

• It has many carbon dioxide releasing organisms.