Across
1
Force that attracts objects together
4
Fourth state of matter
5
Center of an atom or cell
6
Form of thermal energy
10
Absolute temperature scale unit
Down
2
Unit of electric potential
3
Path of a planet around the sun
4
Particle of light
7
Precious yellow metallic element
8
Unit of power
9
Biological catalyst
11
Hottest planet in solar system