Across
1
Force that attracts objects together
3
Basic unit of life
4
Nerve cell in the brain
7
Tissue that contracts for movement
8
Unit of electric potential
11
Measure of matter in an object
12
Gas form of a liquid
Down
2
Gas essential for breathing
3
Solid with repeating atomic pattern
5
Naturally occurring inorganic solid
6
Group of similar cells
9
Compound containing oxygen
10
The Red Planet