Across
1
Magnetic metallic element
4
Ball of burning gas in space
5
Unit of energy
6
Positive particle in nucleus
8
Biological catalyst
12
Preserved remains of ancient life
13
Our home planet
Down
2
Absolute temperature scale unit
3
Hottest planet in solar system
7
Measure of matter in an object
9
Infectious microscopic agent
10
Icy body with a tail near the sun
11
Nerve cell in the brain