Across
1
Ball of burning gas in space
3
Second lightest element
5
Particle of light
8
Force that attracts objects together
9
Unit of electric potential
10
Disturbance that transfers energy
12
Preserved remains of ancient life
Down
2
Blocking of light by a celestial body
4
Path of a planet around the sun
6
Smallest unit of an element
7
Hottest planet in solar system
11
Element found in all living things