Across
1
Blocking of light by a celestial body
3
Measure of matter in an object
6
Force that attracts objects together
7
Amplified beam of light
8
Nerve cell in the brain
11
Tectonic landmass section
12
Disturbance that transfers energy
13
Particle of light
Down
2
Basic unit of life
3
Naturally occurring inorganic solid
4
Reddish electrical conductor
5
Gas essential for breathing
9
The Red Planet
10
Element found in all living things
14
Magnetic metallic element