Across
1
Absolute temperature scale unit
4
Naturally occurring inorganic solid
5
Particle of light
9
Center of an atom or cell
10
Substance with pH above 7
11
Ball of burning gas in space
Down
2
Element found in all living things
3
Nerve cell in the brain
6
Push or pull on an object
7
Glass that splits light into spectrum
8
Natural satellite of Earth
12
Curved glass that refracts light
13
Gas form of a liquid