Discovery of the Electron: Cathode Ray Tube Experiment

TL;DR

JJ Thompson used a cathode ray tube experiment to discover electrons, disproving John Dalton's model of indivisible atoms.

Transcript

in this video we're going to talk about how JJ Thompson discovered the electron in 1897 using the cathode ray tube experiment so these days we think about atoms kind of like this they're made up of a variety of smaller subatomic particles but in the late 1800s it was all about John Dalton's model of the atom in the early 1800s John Dalton had propo... Read More

Key Insights

• 🙌 John Dalton's model of indivisible atoms was challenged by JJ Thompson's discovery of electrons through the cathode ray tube experiment.
• 🙌 Thompson's experiment demonstrated that cathode rays were made up of negatively charged particles, which he named electrons.
• 👻 Thompson's experiments allowed him to determine the size of electrons in comparison to atoms, concluding that electrons were a thousand times smaller.
• 🥺 The discovery of electrons led Thompson to propose the plum pudding model of the atom, where electrons were stuck in a positively charged dough-like structure.

Summary & Key Takeaways

• In the late 1800s, John Dalton proposed that all matter is made up of indivisible atoms, but it remained unknown if atoms were truly indivisible or made of smaller particles.

• JJ Thompson used a cathode ray tube experiment, observing the behavior of cathode rays in the presence of electric charges and magnets, to discover electrons.

• Thompson's experiments led him to conclude that cathode rays were made of negatively charged particles, a thousand times smaller than a hydrogen atom, which he called electrons.