Across
1
Second lightest element
5
Absolute temperature scale unit
6
Precious yellow metallic element
7
Center of an atom or cell
10
Force that attracts objects together
11
Push or pull on an object
12
Tectonic landmass section
Down
2
Basic unit of life
3
Blocking of light by a celestial body
4
Naturally occurring inorganic solid
8
Substance with pH above 7
9
Natural satellite of Earth