Across
1
Gas form of a liquid
3
Biological catalyst
6
Infectious microscopic agent
7
Group of similar cells
10
Substance with pH below 7
Down
2
Smallest unit of an element
4
Curved glass that refracts light
5
Ball of burning gas in space
6
Unit of electric potential
8
Push or pull on an object
9
Center of an atom or cell
11
Unit of heredity
12
Tectonic landmass section
13
Blocking of light by a celestial body