Across
1
Element found in all living things
5
Curved glass that refracts light
6
The Red Planet
8
Tectonic landmass section
10
Disturbance that transfers energy
12
Compound containing oxygen
Down
2
Ball of burning gas in space
3
Biological catalyst
4
Path of a planet around the sun
7
Infectious microscopic agent
8
Positive particle in nucleus
9
Nerve cell in the brain
11
Substance with pH above 7