Across
1
Chemical element in table salt
4
Element found in all living things
5
Molten rock beneath Earth surface
6
Glass that splits light into spectrum
7
Icy body with a tail near the sun
8
Gas essential for breathing
10
Infectious microscopic agent
12
Curved glass that refracts light
13
Unit of electric potential
Down
2
Group of similar cells
3
The Red Planet
4
Basic unit of life
5
Naturally occurring inorganic solid
9
Disturbance that transfers energy
11
Push or pull on an object