Across
1
Substance with pH above 7
2
Nerve cell in the brain
3
Particle of light
5
Gas form of a liquid
6
Solid with repeating atomic pattern
7
Ball of burning gas in space
9
Unit of electric potential
Down
2
Unit of force
3
Tectonic landmass section
4
Path of a planet around the sun
5
Infectious microscopic agent
8
Fourth state of matter