Across
1
Substance with pH above 7
4
Nerve cell in the brain
5
Form of thermal energy
9
The Red Planet
10
Fourth state of matter
12
Icy body with a tail near the sun
Down
2
Unit of power
3
Compound containing oxygen
6
Particle of light
7
Curved glass that refracts light
8
Amplified beam of light
11
Disturbance that transfers energy
13
Positive particle in nucleus