Across
1
Ball of burning gas in space
3
Glass that splits light into spectrum
4
Compound containing oxygen
6
Curved glass that refracts light
8
Unit of energy
9
Second lightest element
10
Absolute temperature scale unit
Down
2
Infectious microscopic agent
3
Tectonic landmass section
5
Mass per unit volume
7
Nerve cell in the brain
11
Push or pull on an object
12
Particle of light
13
Smallest unit of an element