Across
1
Positive particle in nucleus
3
Center of an atom or cell
5
Disturbance that transfers energy
6
Infectious microscopic agent
8
Particle of light
10
Unit of energy
11
Solid with repeating atomic pattern
13
Smallest unit of an element
Down
2
Hottest planet in solar system
4
Ball of burning gas in space
7
Icy body with a tail near the sun
8
Glass that splits light into spectrum
9
Group of similar cells
12
Nerve cell in the brain