Across
1
Naturally occurring inorganic solid
5
Amplified beam of light
6
Our home planet
7
Infectious microscopic agent
10
Force that attracts objects together
11
Substance with pH below 7
Down
2
Center of an atom or cell
3
Group of similar cells
4
Basic unit of life
8
Disturbance that transfers energy
9
Chemical element in table salt
12
Unit of heredity