Across
1
Reddish electrical conductor
3
Nerve cell in the brain
4
Chemical element in table salt
5
Unit of energy
6
Element found in all living things
11
Disturbance that transfers energy
12
Icy body with a tail near the sun
13
Blocking of light by a celestial body
Down
2
Tissue that contracts for movement
3
Center of an atom or cell
7
Particle of light
8
Smallest unit of an element
9
Absolute temperature scale unit
10
Amplified beam of light