Across
1
Magnetic metallic element
4
Biological catalyst
5
Gas essential for breathing
7
Element found in all living things
8
Chemical element in table salt
9
Reddish electrical conductor
15
Fourth state of matter
Down
2
Curved glass that refracts light
3
Group of similar cells
6
Positive particle in nucleus
10
Tectonic landmass section
11
Disturbance that transfers energy
12
Mass per unit volume
13
Naturally occurring inorganic solid
14
Tissue that contracts for movement