Across
1
Absolute temperature scale unit
2
Glass that splits light into spectrum
5
Group of similar cells
6
Icy body with a tail near the sun
9
Substance with pH below 7
11
Center of an atom or cell
Down
2
Particle of light
3
Tectonic landmass section
4
Force that attracts objects together
7
Blocking of light by a celestial body
8
Gas essential for breathing
10
Unit of force