Across
1
Preserved remains of ancient life
5
Absolute temperature scale unit
7
Disturbance that transfers energy
8
Substance with pH below 7
9
Our home planet
11
Reddish electrical conductor
12
Tissue that contracts for movement
13
Chemical element in table salt
Down
2
Ball of burning gas in space
3
Hottest planet in solar system
4
Basic unit of life
6
Compound containing oxygen
10
Blocking of light by a celestial body