Across
1
Positive particle in nucleus
3
Substance with pH below 7
5
Infectious microscopic agent
6
Biological catalyst
9
Amplified beam of light
10
Chemical element in table salt
Down
2
Blocking of light by a celestial body
4
Absolute temperature scale unit
5
Gas form of a liquid
7
Molten rock beneath Earth surface
8
Push or pull on an object
11
Path of a planet around the sun
12
Center of an atom or cell
13
Magnetic metallic element