Across
1
Hottest planet in solar system
4
Force that attracts objects together
8
Compound containing oxygen
9
Icy body with a tail near the sun
11
Mass per unit volume
12
Naturally occurring inorganic solid
Down
2
Form of thermal energy
3
Second lightest element
5
Molten rock beneath Earth surface
6
Magnetic metallic element
7
Smallest unit of an element
10
Group of similar cells