Across
1
Center of an atom or cell
3
Molten rock beneath Earth surface
6
Gas form of a liquid
10
Substance with pH below 7
11
Positive particle in nucleus
Down
2
Magnetic metallic element
3
The Red Planet
4
Push or pull on an object
5
Unit of energy
7
Naturally occurring inorganic solid
8
Substance with pH above 7
9
Gas essential for breathing