“Electrons: they are all around us, but we cannot really see or interact with them. Luckily, there is a device that will let you. A cathode ray tube, or CRT, is a glass tube with electrodes on either end. When there is a vacuum drawn and a high voltage across the two electrodes, a cathode ray forms. This is a stream of electrons that looks like a brilliant blue-purple line of plasma. You can manipulate and bend this stream of electrons with a magnet. This line not only looks cool, but it can be used to prove a scientific theory; electrons are a subatomic unit with a negative charge. I’ll explain how it proves this theory later in this instructable. This piece of test equipment that I will show you how to build can be used as an awesome scientific demonstration for any physics and chemistry class, or it can be used just as a way to confirm a long standing scientific principal. The video below compliments this instructable with a visual demonstration of this Cathode Ray Tube in action. Lets Get Started!”