Across
1
Measure of matter in an object
2
Positive particle in nucleus
4
Hottest planet in solar system
8
Substance with pH above 7
9
Blocking of light by a celestial body
10
Gas form of a liquid
11
Icy body with a tail near the sun
Down
2
Glass that splits light into spectrum
3
Amplified beam of light
5
Form of thermal energy
6
Unit of force
7
Group of similar cells
12
Tectonic landmass section