revision atmosphere class 7

Which gas makes up the largest component of the Earth’s atmosphere?

• argon (Ar)

• oxygen (O₂)

• nitrogen (N₂)

• carbon dioxide (CO₂)

Based on the choices provided, the outermost layer of the atmosphere is called the ___.

• troposphere

• stratosphere

• thermosphere

• mesosphere

Which layer has the coldest average temperature?

• Troposphere

• Stratosphere

• Mesosphere

• Thermosphere

Which statement best describes the ozone layer of Earth?

• It helps reduce the amount of ultraviolet radiation reaching the surface of earth

• It prevents the formation of severe storms in the stratosphere of Earth.

• It increases the amount of nitrogen in the troposphere of Earth.

• It forms a magnetic field in the mesosphere of Earth.

Generally, as altitude increases, temperature ___.

• Increases

• Decreases

• Fluctuates

• Stays constant (the same)

Which layer of the atmosphere has the highest density of gas molecules?

• Exosphere

• Mesosphere

• Stratosphere

• Thermosphere

• Troposphere

In the troposphere, what is true about places at higher altitudes compared to places at lower altitudes?

• they have cooler temperatures

• they have warmer temperatures

• they have the same temperatures

• they have less predictable temperatures

In which atmosphere layer of Earth do thunderstorms occur?

• thermosphere

• mesosphere

• stratosphere

• troposphere

Which is associated with an increase of chlorofluorocarbons in the environment?

• an increase in health risks with UV radiation.

• an increase in levels of methane gas in the atmosphere

• an increase in ozone levels in the upper atmosphere

• an increase in acid precipitation.

Temperature increases as altitude increases in both the stratosphere and the thermosphere. What is the main difference between these two layers?

• The temperature increases in the stratosphere because of aurora borealis, and in the thermosphere because of the jet stream.

• The temperature increases in the stratosphere because ozone absorbs ultraviolet radiation, and in the thermosphere because of direct exposure to the sun.

• The temperature increases in the stratosphere because of direct exposure to the sun, and in the thermosphere because ozone absorbs ultraviolet radiation.

• The temperature increases in the stratosphere because of the jet stream, and in the thermosphere because of aurora borealis.