Across
1
Form of thermal energy
4
Nerve cell in the brain
5
Blocking of light by a celestial body
10
Force that attracts objects together
12
Compound containing oxygen
13
Gas form of a liquid
14
Unit of power
Down
2
Our home planet
3
Substance with pH below 7
6
Path of a planet around the sun
7
Tectonic landmass section
8
Gas essential for breathing
9
Element found in all living things
11
Basic unit of life