Across
1
Fourth state of matter
4
Unit of force
5
Naturally occurring inorganic solid
6
Curved glass that refracts light
9
Gas essential for breathing
11
Ball of burning gas in space
12
Our home planet
13
Glass that splits light into spectrum
Down
2
Measure of matter in an object
3
Chemical element in table salt
7
Center of an atom or cell
8
Biological catalyst
10
Force that attracts objects together