Across
1
Glass that splits light into spectrum
4
Unit of force
5
Element found in all living things
7
Gas essential for breathing
10
Second lightest element
Down
1
Positive particle in nucleus
2
Natural satellite of Earth
3
Magnetic metallic element
6
Hottest planet in solar system
8
Path of a planet around the sun
9
Ball of burning gas in space
11
Center of an atom or cell
12
Mass per unit volume
13
Force that attracts objects together