Across
1
Icy body with a tail near the sun
2
Disturbance that transfers energy
4
Molten rock beneath Earth surface
5
Unit of electric potential
8
Substance with pH above 7
9
Push or pull on an object
Down
1
Element found in all living things
2
Unit of power
3
Fourth state of matter
6
Ball of burning gas in space
7
Biological catalyst