Across
1
Element found in all living things
4
Measure of matter in an object
5
Mass per unit volume
9
Absolute temperature scale unit
11
Form of thermal energy
Down
2
Gas essential for breathing
3
The Red Planet
6
Particle of light
7
Substance with pH below 7
8
Positive particle in nucleus
10
Amplified beam of light
12
Reddish electrical conductor