Across
1
Tissue that contracts for movement
4
Positive particle in nucleus
7
Glass that splits light into spectrum
8
Path of a planet around the sun
9
Fourth state of matter
11
The Red Planet
Down
2
Smallest unit of an element
3
Substance with pH below 7
5
Unit of energy
6
Solid with repeating atomic pattern
7
Particle of light
10
Form of thermal energy