Across
1
Positive particle in nucleus
3
Absolute temperature scale unit
4
Hottest planet in solar system
6
Smallest unit of an element
7
Fourth state of matter
9
Preserved remains of ancient life
10
Blocking of light by a celestial body
Down
1
Glass that splits light into spectrum
2
Center of an atom or cell
5
Ball of burning gas in space
6
Substance with pH below 7
8
Tissue that contracts for movement