Across
1
Ball of burning gas in space
3
Unit of force
4
Tissue that contracts for movement
7
Particle of light
9
Substance with pH above 7
10
Second lightest element
11
Mass per unit volume
Down
1
Chemical element in table salt
2
Push or pull on an object
5
Solid with repeating atomic pattern
6
Nerve cell in the brain
8
Form of thermal energy
12
Unit of power