Across
1
Biological catalyst
4
Group of similar cells
5
Substance with pH above 7
7
Magnetic metallic element
8
Substance with pH below 7
11
Curved glass that refracts light
12
Positive particle in nucleus
Down
2
Element found in all living things
3
Compound containing oxygen
6
Naturally occurring inorganic solid
9
Hottest planet in solar system
10
Our home planet