Across
1
Natural satellite of Earth
3
Basic unit of life
4
Mass per unit volume
8
Gas form of a liquid
12
Solid with repeating atomic pattern
Down
2
Gas essential for breathing
5
Ball of burning gas in space
6
Hottest planet in solar system
7
Group of similar cells
9
Amplified beam of light
10
Glass that splits light into spectrum
11
Molten rock beneath Earth surface
13
Compound containing oxygen