Across
1
Center of an atom or cell
3
Tectonic landmass section
5
Unit of power
7
Substance with pH above 7
8
Compound containing oxygen
11
Amplified beam of light
12
Path of a planet around the sun
Down
2
Preserved remains of ancient life
3
Fourth state of matter
4
Icy body with a tail near the sun
6
Second lightest element
9
Unit of force
10
Positive particle in nucleus