Across
1
Group of similar cells
2
Icy body with a tail near the sun
5
Preserved remains of ancient life
8
Hottest planet in solar system
10
Fourth state of matter
11
Substance with pH below 7
12
Naturally occurring inorganic solid
Down
2
Basic unit of life
3
Unit of power
4
Solid with repeating atomic pattern
6
Nerve cell in the brain
7
Gas form of a liquid
9
Our home planet