Across
1
Center of an atom or cell
3
Gas form of a liquid
6
Our home planet
9
Nerve cell in the brain
10
Mass per unit volume
11
Force that attracts objects together
Down
2
Solid with repeating atomic pattern
4
Precious yellow metallic element
5
Tectonic landmass section
7
Natural satellite of Earth
8
Path of a planet around the sun
12
Absolute temperature scale unit
13
Blocking of light by a celestial body
14
Glass that splits light into spectrum