Across
1
Form of thermal energy
3
Preserved remains of ancient life
5
Naturally occurring inorganic solid
6
Push or pull on an object
7
Reddish electrical conductor
8
Substance with pH below 7
10
Particle of light
Down
2
Center of an atom or cell
4
Compound containing oxygen
7
Icy body with a tail near the sun
9
Precious yellow metallic element
11
Second lightest element