Across
1
Chemical element in table salt
3
Positive particle in nucleus
5
Center of an atom or cell
7
Disturbance that transfers energy
11
Amplified beam of light
Down
2
Nerve cell in the brain
4
Absolute temperature scale unit
6
Blocking of light by a celestial body
8
Molten rock beneath Earth surface
9
Reddish electrical conductor
10
Substance with pH below 7