Across
1
Positive particle in nucleus
4
Fourth state of matter
5
Icy body with a tail near the sun
8
Gas essential for breathing
Down
1
Glass that splits light into spectrum
2
Curved glass that refracts light
3
Path of a planet around the sun
6
Center of an atom or cell
7
Blocking of light by a celestial body
9
Gas form of a liquid
10
Molten rock beneath Earth surface