Across
1
Tectonic landmass section
4
Measure of matter in an object
6
Center of an atom or cell
7
Precious yellow metallic element
9
Path of a planet around the sun
11
Form of thermal energy
Down
2
Solid with repeating atomic pattern
3
Substance with pH below 7
5
Unit of energy
7
Force that attracts objects together
8
Glass that splits light into spectrum
10
Gas essential for breathing