Across
1
Center of an atom or cell
4
Element found in all living things
5
Reddish electrical conductor
6
Form of thermal energy
7
Second lightest element
12
Compound containing oxygen
Down
2
Particle of light
3
Unit of electric potential
4
Solid with repeating atomic pattern
8
Amplified beam of light
9
Our home planet
10
The Red Planet
11
Path of a planet around the sun
13
Positive particle in nucleus