Discovery/Theory card
![](https://phylogame.org/wp-content/themes/phylo/img/generated-card-images/br-4650C3----1.png)
Discovery/Theory card
Cathode Ray tube![](https://phylogame.org/wp-content/uploads/2016/05/Screen-Shot-2016-05-04-at-8.25.12-PM.png)
Parker POINTS
The two electrodes produce a greenish glow called fluorescence when they are connected to power / A beam of negative particles produces a shadow coming from the disk shaped electrode, called a cathode / This lead to scientists realizing that these particles of matter must be smaller than the atom.
Graphic by Eric Hamber Secondary