Across
1
Mass per unit volume
5
Group of similar cells
6
Disturbance that transfers energy
7
Particle of light
10
Tectonic landmass section
11
Unit of energy
12
Amplified beam of light
13
Ball of burning gas in space
Down
2
Blocking of light by a celestial body
3
Hottest planet in solar system
4
Our home planet
7
Glass that splits light into spectrum
8
Center of an atom or cell
9
Infectious microscopic agent