Across
1
Tissue that contracts for movement
4
Unit of electric potential
6
Mass per unit volume
8
Glass that splits light into spectrum
9
Second lightest element
10
Gas essential for breathing
12
Center of an atom or cell
Down
2
Solid with repeating atomic pattern
3
Unit of energy
4
Infectious microscopic agent
5
Chemical element in table salt
7
Particle of light
11
Disturbance that transfers energy