Across
1
Ball of burning gas in space
4
Form of thermal energy
5
Magnetic metallic element
8
Amplified beam of light
9
Unit of force
10
Gas essential for breathing
11
Substance with pH above 7
Down
2
Substance with pH below 7
3
Blocking of light by a celestial body
6
Hottest planet in solar system
7
Particle of light