Across
1
Second lightest element
3
Unit of electric potential
5
Gas form of a liquid
6
Icy body with a tail near the sun
7
Compound containing oxygen
9
Curved glass that refracts light
10
Unit of energy
11
Glass that splits light into spectrum
Down
2
Chemical element in table salt
4
Our home planet
5
Hottest planet in solar system
8
Group of similar cells
12
Absolute temperature scale unit