Across
1
Nerve cell in the brain
4
Absolute temperature scale unit
5
Curved glass that refracts light
6
Magnetic metallic element
9
Push or pull on an object
11
Measure of matter in an object
12
The Red Planet
Down
2
Group of similar cells
3
Preserved remains of ancient life
7
Element found in all living things
8
Biological catalyst
10
Path of a planet around the sun
13
Hottest planet in solar system