Across
1
Gas essential for breathing
3
Center of an atom or cell
4
Unit of electric potential
5
Reddish electrical conductor
8
Amplified beam of light
10
Naturally occurring inorganic solid
12
Blocking of light by a celestial body
Down
2
Unit of heredity
3
Unit of force
4
Infectious microscopic agent
6
Substance with pH below 7
7
Solid with repeating atomic pattern
9
Hottest planet in solar system
10
Molten rock beneath Earth surface
11
Second lightest element