Across
1
Naturally occurring inorganic solid
3
Natural satellite of Earth
6
Precious yellow metallic element
7
Force that attracts objects together
9
Blocking of light by a celestial body
10
Element found in all living things
11
Magnetic metallic element
Down
2
Mass per unit volume
4
Hottest planet in solar system
5
Center of an atom or cell
8
Smallest unit of an element
12
Curved glass that refracts light
13
Ball of burning gas in space