Across
1
Particle of light
5
Amplified beam of light
7
Substance with pH above 7
9
Group of similar cells
11
Form of thermal energy
12
Unit of electric potential
Down
2
Reddish electrical conductor
3
Path of a planet around the sun
4
Unit of power
6
Solid with repeating atomic pattern
8
Gas essential for breathing
10
The Red Planet
13
Our home planet