Across
1
Gas form of a liquid
3
Reddish electrical conductor
5
Nerve cell in the brain
6
Biological catalyst
8
Form of thermal energy
11
Curved glass that refracts light
12
Hottest planet in solar system
Down
2
Positive particle in nucleus
3
Solid with repeating atomic pattern
4
Molten rock beneath Earth surface
7
Naturally occurring inorganic solid
9
Unit of force
10
Natural satellite of Earth