Across
1
Biological catalyst
4
Path of a planet around the sun
6
Particle of light
8
Curved glass that refracts light
10
Force that attracts objects together
Down
2
Push or pull on an object
3
Glass that splits light into spectrum
5
Mass per unit volume
6
Fourth state of matter
7
Our home planet
9
Nerve cell in the brain
11
Magnetic metallic element