1.
The smallest unit of matter
2.
A group of atoms bonded together
3.
The process plants use to make food from sunlight
4.
The force that pulls objects toward Earth
5.
A force that slows objects down when they touch
6.
The process of liquid turning into gas
7.
The process of gas turning back into liquid
8.
Relating to the movement of Earth's crust
9.
The speed and direction of a moving object
10.
The amount of mass in a given volume
11.
A system of living and non-living things interacting
12.
The process of breathing and energy release in cells
13.
A nerve cell that carries messages in the body
14.
The measure of electric potential difference
15.
The force that attracts or repels certain metals
16.
The bouncing back of light from a surface
17.
The bending of light when it passes through different materials
18.
A closed loop through which electricity flows
19.
A structure in cells that carries genetic information
20.
A protein that speeds up chemical reactions in the body
