Across
1
Gas essential for breathing
3
Form of thermal energy
5
Element found in all living things
10
Hottest planet in solar system
11
Blocking of light by a celestial body
12
Chemical element in table salt
Down
2
Substance with pH above 7
4
Natural satellite of Earth
6
Infectious microscopic agent
7
Center of an atom or cell
8
Compound containing oxygen
9
Precious yellow metallic element
13
Molten rock beneath Earth surface