Across
1
Solid with repeating atomic pattern
5
Tissue that contracts for movement
6
Fourth state of matter
7
Ball of burning gas in space
13
Mass per unit volume
Down
2
Naturally occurring inorganic solid
3
Unit of electric potential
4
Preserved remains of ancient life
8
Disturbance that transfers energy
9
Glass that splits light into spectrum
10
The Red Planet
11
Reddish electrical conductor
12
Substance with pH below 7