Across
1
Substance with pH above 7
4
Icy body with a tail near the sun
5
Hottest planet in solar system
7
Tissue that contracts for movement
10
Measure of matter in an object
12
Smallest unit of an element
13
Unit of force
Down
2
Naturally occurring inorganic solid
3
Disturbance that transfers energy
6
Solid with repeating atomic pattern
8
Particle of light
9
Nerve cell in the brain
11
Compound containing oxygen