Across
1
Reddish electrical conductor
4
Ball of burning gas in space
8
Curved glass that refracts light
9
Smallest unit of an element
10
Measure of matter in an object
11
Icy body with a tail near the sun
Down
2
Glass that splits light into spectrum
3
Hottest planet in solar system
5
Group of similar cells
6
Center of an atom or cell
7
Gas form of a liquid