Across
1
Force that attracts objects together
4
Disturbance that transfers energy
6
Center of an atom or cell
7
Push or pull on an object
11
Curved glass that refracts light
Down
2
Gas essential for breathing
3
Element found in all living things
5
Particle of light
8
Form of thermal energy
9
Infectious microscopic agent
10
Amplified beam of light
12
Substance with pH above 7