Across
1
Nerve cell in the brain
4
Gas essential for breathing
5
Tectonic landmass section
6
Precious yellow metallic element
9
Tissue that contracts for movement
10
Smallest unit of an element
Down
2
Hottest planet in solar system
3
Mass per unit volume
4
Compound containing oxygen
7
Force that attracts objects together
8
Basic unit of life
11
Substance with pH above 7