Across
1
Mass per unit volume
4
Reddish electrical conductor
5
Blocking of light by a celestial body
7
Amplified beam of light
9
Molten rock beneath Earth surface
12
Gas essential for breathing
14
Unit of force
15
Our home planet
Down
2
Unit of energy
3
Chemical element in table salt
6
Ball of burning gas in space
8
Form of thermal energy
10
Natural satellite of Earth
11
Gas form of a liquid
13
Tissue that contracts for movement