Across
1
Nerve cell in the brain
3
The Red Planet
5
Tissue that contracts for movement
6
Blocking of light by a celestial body
9
Gas essential for breathing
12
Magnetic metallic element
Down
2
Chemical element in table salt
4
Hottest planet in solar system
7
Naturally occurring inorganic solid
8
Element found in all living things
10
Center of an atom or cell
11
Unit of heredity