Across
1
Gas form of a liquid
4
Push or pull on an object
5
Center of an atom or cell
6
Fourth state of matter
7
Mass per unit volume
10
Element found in all living things
Down
2
Naturally occurring inorganic solid
3
Reddish electrical conductor
8
Force that attracts objects together
9
Hottest planet in solar system
11
Smallest unit of an element