Across
1
Icy body with a tail near the sun
4
Glass that splits light into spectrum
6
Element found in all living things
7
Push or pull on an object
10
Ball of burning gas in space
11
Force that attracts objects together
12
Naturally occurring inorganic solid
Down
2
Center of an atom or cell
3
Measure of matter in an object
5
Unit of power
8
Natural satellite of Earth
9
Infectious microscopic agent