Across
1
Reddish electrical conductor
2
Icy body with a tail near the sun
3
Molten rock beneath Earth surface
4
Gas essential for breathing
5
Mass per unit volume
7
Magnetic metallic element
9
Second lightest element
Down
1
Element found in all living things
2
Solid with repeating atomic pattern
6
Positive particle in nucleus
8
Biological catalyst
10
Compound containing oxygen
11
Our home planet