Energy Review

What is the atmosphere?

• A thin layer of gases that surrounds the Earth.
• A thin layer of liquid that surrounds Earth.
• A sphere that floats in the air

What is the most common molecule in the mixture of gases that make up air?

• carbon dioxide (CO₂)
• oxygen gas (O2)
• nitrogen gas (N₂)

Which natural materials cycle through living things, the land, and the air?

• only water
• only carbon
• carbon, water, and nitrogen
• only nitrogen

Which of these conditions is MOST responsible for Earth having an environment that supports life?

• oceans regulating climate on land

• the percentage of nitrogen in the atmosphere

• water that exists in all three physical states of matter

• erupting volcanoes moderating atmospheric temperatures

Life is more likely to be found on a planet whose atmosphere contains abundant

• neon

• oxygen

• hydrogen

• sulfur dioxide

Earth’s distance from the Sun helps the planet sustain life. If the Sun were larger, what would MOST likely also have to be true for Earth to sustain life?

• Earth would have to be further from the Sun.

• Earth would have to be closer to the Sun.

• Earth would have to be smaller.

• Earth would have to be larger.

fuels formed from decaying remains of plants and animals that lived millions of years go

• conservation
• hydroelectric power
• nonrenewable resources
• fossil fuels

natural resources that nature can produce again, such as tress, plants, animals, water, oxygen, and soil

• renewable resources
• nonrenewable resources 
• alternative energy source
• geothermal energy

natural resources, such as fossil fuels, that will eventually be used up and can never be replalced

• renewable resource
• biofuels
• hydroelectric energy
• nonrenewable resources

alternative energy sources

• fuels made from organic matter
• heat energy naturally produced within Earth
• sources of energy that do not come from fossil fuels
• materials in the environment that are useful to people