Across
1
Fourth state of matter
2
Positive particle in nucleus
3
Gas essential for breathing
4
Natural satellite of Earth
6
Absolute temperature scale unit
8
Blocking of light by a celestial body
Down
1
Particle of light
5
Unit of heredity
7
Hottest planet in solar system
9
Precious yellow metallic element
10
Magnetic metallic element
11
Second lightest element