Across
1
Tissue that contracts for movement
5
Path of a planet around the sun
6
Naturally occurring inorganic solid
8
Center of an atom or cell
11
Chemical element in table salt
Down
2
Fourth state of matter
3
Reddish electrical conductor
4
Gas essential for breathing
7
Infectious microscopic agent
9
Disturbance that transfers energy
10
Our home planet
12
Magnetic metallic element