Across
1
Center of an atom or cell
4
Gas form of a liquid
7
Naturally occurring inorganic solid
10
Reddish electrical conductor
Down
2
Amplified beam of light
3
Blocking of light by a celestial body
5
Unit of power
6
Infectious microscopic agent
8
The Red Planet
9
Compound containing oxygen
11
Natural satellite of Earth
12
Unit of energy