Across
1
Curved glass that refracts light
3
Particle of light
5
Fourth state of matter
6
Tectonic landmass section
9
Icy body with a tail near the sun
10
Biological catalyst
13
Element found in all living things
Down
2
Push or pull on an object
4
Reddish electrical conductor
5
Positive particle in nucleus
7
Unit of force
8
The Red Planet
11
Gas essential for breathing
12
Substance with pH above 7