Across
1
Hottest planet in solar system
4
Smallest unit of an element
6
Blocking of light by a celestial body
9
Tectonic landmass section
10
Gas form of a liquid
12
Substance with pH below 7
Down
2
Disturbance that transfers energy
3
Amplified beam of light
5
Element found in all living things
7
Gas essential for breathing
8
Path of a planet around the sun
11
Absolute temperature scale unit