Across
1
Push or pull on an object
3
Nerve cell in the brain
4
Substance with pH below 7
6
Ball of burning gas in space
7
Icy body with a tail near the sun
10
The Red Planet
Down
2
Compound containing oxygen
3
Center of an atom or cell
5
Reddish electrical conductor
7
Basic unit of life
8
Gas form of a liquid
9
Hottest planet in solar system
10
Measure of matter in an object
11
Unit of force