Across
1
Smallest unit of an element
2
Reddish electrical conductor
5
Preserved remains of ancient life
6
Element found in all living things
9
Fourth state of matter
Down
1
Substance with pH below 7
2
Icy body with a tail near the sun
3
Basic unit of life
4
Molten rock beneath Earth surface
7
Infectious microscopic agent
8
Unit of energy