Across
1
Absolute temperature scale unit
4
Ball of burning gas in space
6
Gas essential for breathing
8
Curved glass that refracts light
10
Push or pull on an object
11
Unit of electric potential
12
Second lightest element
13
Blocking of light by a celestial body
15
Substance with pH above 7
Down
2
Our home planet
3
Particle of light
5
Measure of matter in an object
7
Element found in all living things
9
Magnetic metallic element
14
Form of thermal energy