Across
1
Unit of electric potential
4
Particle of light
5
The Red Planet
7
Curved glass that refracts light
9
Molten rock beneath Earth surface
11
Substance with pH below 7
Down
2
Our home planet
3
Path of a planet around the sun
4
Fourth state of matter
6
Hottest planet in solar system
8
Center of an atom or cell
10
Amplified beam of light