Across
1
Center of an atom or cell
3
Smallest unit of an element
6
Nerve cell in the brain
8
Preserved remains of ancient life
12
Tectonic landmass section
Down
2
The Red Planet
4
Natural satellite of Earth
5
Unit of force
7
Unit of power
9
Naturally occurring inorganic solid
10
Unit of electric potential
11
Hottest planet in solar system