Across
1
Glass that splits light into spectrum
3
Center of an atom or cell
6
Icy body with a tail near the sun
7
Smallest unit of an element
8
Natural satellite of Earth
9
Ball of burning gas in space
10
Substance with pH above 7
Down
2
Compound containing oxygen
4
Measure of matter in an object
5
Biological catalyst
11
Second lightest element
12
Path of a planet around the sun