Across
1
Center of an atom or cell
3
Natural satellite of Earth
5
Tectonic landmass section
8
Biological catalyst
11
Amplified beam of light
Down
2
Second lightest element
3
The Red Planet
4
Basic unit of life
6
Gas essential for breathing
7
Unit of power
9
Unit of force
10
Disturbance that transfers energy
12
Precious yellow metallic element