Across
1
Second lightest element
3
Tectonic landmass section
5
Unit of force
7
Infectious microscopic agent
8
Ball of burning gas in space
9
Path of a planet around the sun
11
Precious yellow metallic element
Down
2
Substance with pH below 7
3
Glass that splits light into spectrum
4
Nerve cell in the brain
6
Mass per unit volume
10
Biological catalyst