Across
1
Positive particle in nucleus
5
Unit of power
6
Fourth state of matter
9
Ball of burning gas in space
10
Form of thermal energy
12
Biological catalyst
Down
2
Gas form of a liquid
3
Natural satellite of Earth
4
Path of a planet around the sun
5
Disturbance that transfers energy
7
Element found in all living things
8
Infectious microscopic agent
11
Naturally occurring inorganic solid