Across
1
Unit of force
4
Substance with pH above 7
5
Unit of energy
7
Infectious microscopic agent
8
Center of an atom or cell
10
Natural satellite of Earth
11
Second lightest element
Down
2
Absolute temperature scale unit
3
Gas essential for breathing
6
Push or pull on an object
9
Smallest unit of an element
10
Measure of matter in an object
12
Icy body with a tail near the sun
13
Blocking of light by a celestial body
14
Ball of burning gas in space