Across
1
Particle of light
5
Center of an atom or cell
7
The Red Planet
8
Reddish electrical conductor
10
Ball of burning gas in space
Down
2
Precious yellow metallic element
3
Compound containing oxygen
4
Gas form of a liquid
6
Chemical element in table salt
9
Measure of matter in an object
11
Blocking of light by a celestial body
12
Unit of force