Across
1
Blocking of light by a celestial body
6
Second lightest element
7
Measure of matter in an object
8
Fourth state of matter
10
Precious yellow metallic element
11
Unit of force
Down
2
Group of similar cells
3
Tissue that contracts for movement
4
Compound containing oxygen
5
Ball of burning gas in space
9
Biological catalyst
12
Basic unit of life
13
Unit of power