Year 8 Earth

What is the definition of the carbon cycle?

• The process plants and algae use to make their own food, glucose.

• The mixture of gases surrounding the Earth.

• The carbon cycle shows carbon sinks, and summarises how carbon and its compounds enter and leave the atmosphere and these sinks.

• A long-term change in weather patterns.

What does the term 'combustion' refer to?

• Using electricity to split up a compound into its elements.

• The gradual increase in the average surface temperature of the Earth.

• A chemical reaction in which a substance reacts quickly with oxygen and gives out light and heat.

• Collecting and processing a material so that it can be used again.

Which of the following best describes 'electrolysis'?

• The process that transfers energy in plants and animals.

• Using electricity to split up a compound into its elements.

• The separation of a metal from a metal compound.

• A naturally occurring rock that contains enough of a mineral to make it worth getting the mineral.

What is the role of 'greenhouse gases' in the environment?

• They contribute to the carbon cycle by absorbing and storing carbon.

• They are naturally occurring metals and their compounds.

• They contribute to the greenhouse effect, such as carbon dioxide.

• They are materials from the Earth used as raw materials for making a variety of products.

What is 'photosynthesis'?

• The process by which a substance reacts quickly with oxygen and gives out light and heat.

• The process plants and algae use to make their own food, glucose.

• The mixture of gases surrounding the Earth.

• The separation of a metal from a metal compound.

What is 'respiration'?

• The process that transfers energy in plants and animals, where glucose reacts with oxygen to make carbon dioxide and water.

• The process of collecting and processing a material so that it can be used again.

• The gradual increase in the average surface temperature of the Earth.

• The chemical reaction in which a substance reacts quickly with oxygen and gives out light and heat.