Across
1
Measure of matter in an object
4
The Red Planet
5
Unit of power
7
Center of an atom or cell
9
Our home planet
10
Curved glass that refracts light
Down
2
Chemical element in table salt
3
Fourth state of matter
6
Icy body with a tail near the sun
8
Hottest planet in solar system
11
Nerve cell in the brain