Across
1
Curved glass that refracts light
4
Positive particle in nucleus
6
Nerve cell in the brain
7
Push or pull on an object
9
Mass per unit volume
10
Glass that splits light into spectrum
11
Substance with pH below 7
Down
2
Measure of matter in an object
3
Compound containing oxygen
5
Element found in all living things
8
Biological catalyst