Across
1
Curved glass that refracts light
2
Tissue that contracts for movement
4
Substance with pH above 7
5
Force that attracts objects together
7
Particle of light
Down
1
Amplified beam of light
2
Measure of matter in an object
3
Group of similar cells
6
Gas form of a liquid
8
Nerve cell in the brain
9
Element found in all living things