Across
1
Positive particle in nucleus
3
The Red Planet
4
Fourth state of matter
6
Disturbance that transfers energy
9
Magnetic metallic element
10
Center of an atom or cell
Down
2
Blocking of light by a celestial body
5
Force that attracts objects together
7
Measure of matter in an object
8
Nerve cell in the brain
11
Element found in all living things