science

biology

100

I am the organ that pumps blood through your body.

heart

200

I am the basic unit of life.

cell

300

I am the process by which plants make food using sunlight.

Photosynthesis

400

I am the system that breaks down food so your body can use it.

digestive system

500

I am the molecule that carries genetic information.

DNA

space and astronomy

100

I am the planet closest to the Sun.

Mercury

200

I am the galaxy that contains our Solar System.

milky way

300

I am the red planet, often called the “Red Planet.”

mars

400

I am the force that keeps planets in orbit around the Sun.

gravity

500

I am the explosion that happens at the end of a massive star’s life.

supernova

chemistry

100

I am the chemical symbol for water

H2O

200

I am a gas that humans breathe in to survive.

oxygen

300

I am the smallest particle of an eleme

atom

400

I am a substance made of two or more elements chemically combined

compound

500

I am a change that creates a new substance, like burning wood.

chemical reactions

Earth and environment

100

I am the layer of air surrounding Earth.

atmosphere

200

I am the process where water moves from the Earth to the sky and back

water cycle

300

I am the planet’s outer layer of rock.

crust

400

I am the natural resource used to make electricity in power plants, like coal or uranium

energy/fuel

500

I am a large, slow-moving river of ice

Glacier