Across
1
Mass per unit volume
2
Basic unit of life
5
Amplified beam of light
8
Solid with repeating atomic pattern
9
Chemical element in table salt
10
Unit of heredity
Down
2
Icy body with a tail near the sun
3
Precious yellow metallic element
4
Force that attracts objects together
6
Infectious microscopic agent
7
Center of an atom or cell