Across
1
Second lightest element
4
Push or pull on an object
5
Naturally occurring inorganic solid
8
Substance with pH below 7
10
Chemical element in table salt
Down
1
Form of thermal energy
2
The Red Planet
3
Disturbance that transfers energy
4
Preserved remains of ancient life
6
Tissue that contracts for movement
7
Compound containing oxygen
9
Unit of force