Across
1
Hottest planet in solar system
4
Center of an atom or cell
5
Glass that splits light into spectrum
8
Substance with pH below 7
10
Positive particle in nucleus
11
Basic unit of life
Down
2
Blocking of light by a celestial body
3
Unit of energy
6
Group of similar cells
7
Unit of heredity
9
Solid with repeating atomic pattern
11
Icy body with a tail near the sun
12
Natural satellite of Earth