Across
1
Ball of burning gas in space
3
Compound containing oxygen
5
Unit of force
6
Infectious microscopic agent
9
Magnetic metallic element
10
Nerve cell in the brain
Down
1
Chemical element in table salt
2
Push or pull on an object
4
Gas essential for breathing
7
Icy body with a tail near the sun
8
Group of similar cells
11
Substance with pH below 7