Across
1
Tectonic landmass section
2
Force that attracts objects together
3
Gas essential for breathing
6
Substance with pH below 7
8
Infectious microscopic agent
10
Curved glass that refracts light
Down
2
Unit of heredity
4
Hottest planet in solar system
5
Amplified beam of light
7
Center of an atom or cell
9
Solid with repeating atomic pattern