Across
1
Push or pull on an object
3
Unit of power
7
Center of an atom or cell
9
Our home planet
10
Curved glass that refracts light
12
Positive particle in nucleus
Down
2
Path of a planet around the sun
4
Reddish electrical conductor
5
Tectonic landmass section
6
Group of similar cells
8
Natural satellite of Earth
11
Mass per unit volume
13
Unit of energy