Across
1
Tectonic landmass section
4
Positive particle in nucleus
5
Curved glass that refracts light
8
Our home planet
9
Unit of power
10
Naturally occurring inorganic solid
11
Unit of force
Down
2
Unit of heredity
3
Unit of energy
4
Fourth state of matter
6
Ball of burning gas in space
7
Nerve cell in the brain
8
Blocking of light by a celestial body
12
Glass that splits light into spectrum