Across
1
Measure of matter in an object
3
Compound containing oxygen
5
Infectious microscopic agent
7
Force that attracts objects together
9
Path of a planet around the sun
10
Curved glass that refracts light
Down
2
Center of an atom or cell
4
Substance with pH below 7
6
Disturbance that transfers energy
8
Solid with repeating atomic pattern
11
Our home planet