Across
1
Fourth state of matter
4
Push or pull on an object
5
Naturally occurring inorganic solid
8
Form of thermal energy
9
Force that attracts objects together
10
Nerve cell in the brain
11
Hottest planet in solar system
Down
2
Smallest unit of an element
3
Basic unit of life
5
Tissue that contracts for movement
6
Our home planet
7
Preserved remains of ancient life