Across
1
Push or pull on an object
3
Biological catalyst
4
Mass per unit volume
7
Tectonic landmass section
8
Icy body with a tail near the sun
9
Natural satellite of Earth
12
Gas essential for breathing
Down
2
Tissue that contracts for movement
5
Form of thermal energy
6
Unit of force
7
Particle of light
10
Group of similar cells
11
Unit of energy