Across
1
Ball of burning gas in space
3
Group of similar cells
4
Icy body with a tail near the sun
6
Fourth state of matter
7
Molten rock beneath Earth surface
8
Disturbance that transfers energy
10
Biological catalyst
Down
2
Form of thermal energy
4
Solid with repeating atomic pattern
5
Curved glass that refracts light
6
Particle of light
9
Our home planet