Across
1
Force that attracts objects together
4
Naturally occurring inorganic solid
6
Blocking of light by a celestial body
7
Nerve cell in the brain
13
Infectious microscopic agent
Down
2
Unit of force
3
Measure of matter in an object
5
Unit of power
8
Particle of light
9
Element found in all living things
10
Tectonic landmass section
11
Reddish electrical conductor
12
Disturbance that transfers energy