Across
1
Chemical element in table salt
5
Unit of power
7
Group of similar cells
8
Substance with pH below 7
9
Blocking of light by a celestial body
10
Second lightest element
Down
2
Center of an atom or cell
3
Infectious microscopic agent
4
Molten rock beneath Earth surface
6
Our home planet
11
Precious yellow metallic element
12
Tissue that contracts for movement