Across
1
Mass per unit volume
3
Disturbance that transfers energy
6
Gas form of a liquid
7
Icy body with a tail near the sun
9
Unit of energy
11
Unit of electric potential
Down
2
Compound containing oxygen
4
Curved glass that refracts light
5
Smallest unit of an element
8
Element found in all living things
10
Path of a planet around the sun