Across
1
Nerve cell in the brain
3
Second lightest element
7
Absolute temperature scale unit
8
Tectonic landmass section
9
Disturbance that transfers energy
10
Glass that splits light into spectrum
11
Naturally occurring inorganic solid
12
Unit of heredity
13
Preserved remains of ancient life
Down
2
Group of similar cells
4
Positive particle in nucleus
5
Gas essential for breathing
6
Our home planet
14
Infectious microscopic agent