Across
1
Particle of light
4
Compound containing oxygen
5
Molten rock beneath Earth surface
7
Nerve cell in the brain
8
Form of thermal energy
11
Biological catalyst
Down
1
Glass that splits light into spectrum
2
Hottest planet in solar system
3
Tectonic landmass section
6
Element found in all living things
7
Unit of force
9
Positive particle in nucleus
10
Force that attracts objects together
12
Substance with pH below 7
13
The Red Planet