Across
1
Magnetic metallic element
3
Second lightest element
4
Icy body with a tail near the sun
5
Mass per unit volume
7
Particle of light
9
Molten rock beneath Earth surface
13
Blocking of light by a celestial body
Down
2
Our home planet
4
Solid with repeating atomic pattern
6
Smallest unit of an element
8
Unit of force
10
Hottest planet in solar system
11
Naturally occurring inorganic solid
12
Tissue that contracts for movement