Across
1
Center of an atom or cell
3
Smallest unit of an element
7
Ball of burning gas in space
9
Absolute temperature scale unit
11
Force that attracts objects together
12
Path of a planet around the sun
Down
2
Compound containing oxygen
4
Form of thermal energy
5
Biological catalyst
6
Measure of matter in an object
8
Infectious microscopic agent
10
Chemical element in table salt