Across
1
Ball of burning gas in space
3
Biological catalyst
5
Magnetic metallic element
7
Unit of electric potential
8
Tissue that contracts for movement
11
Force that attracts objects together
12
Particle of light
Down
2
Element found in all living things
4
Second lightest element
6
Solid with repeating atomic pattern
9
Fourth state of matter
10
Center of an atom or cell