Across
1
Mass per unit volume
4
Glass that splits light into spectrum
5
Center of an atom or cell
9
Disturbance that transfers energy
10
Molten rock beneath Earth surface
12
Nerve cell in the brain
13
Naturally occurring inorganic solid
Down
2
The Red Planet
3
Absolute temperature scale unit
6
Second lightest element
7
Chemical element in table salt
8
Unit of power
11
Reddish electrical conductor
14
Preserved remains of ancient life