Across
1
Fourth state of matter
2
Tissue that contracts for movement
4
Reddish electrical conductor
5
Unit of electric potential
8
Second lightest element
9
Magnetic metallic element
Down
2
Naturally occurring inorganic solid
3
Icy body with a tail near the sun
6
Center of an atom or cell
7
Curved glass that refracts light
10
Our home planet