J.J. Thomson's Experiment & Millikan's Oil Drop Experiment | Class 11 Chemistry Ch 2 | CBSE 2024-25

Magnet Brains・2 minutes read

Welcome to Magnet Brains, a channel offering free quality education by Self Himmat, discussing Class 11th Chemistry Chapter Number Tu on the Structure of Atom. Thomson discovered the electron and its charge by mass ratio, while Millieux conducted the Propane Oil Drop experiment to determine the charge on an electron, crucial for understanding electron properties.

Insights

  • Sir J Thomson's experiments led to the discovery of the electron and the calculation of its charge-to-mass ratio, which was found to be 1.75 * 10^11 Coulomb/K. This groundbreaking research paved the way for further investigations into the structure of the atom.
  • The Milikan Oil Drop Experiment, conducted by Million Sir and Militant Sir, determined the charge on a single electron to be 1.6 * 10^-19 Coulombs. This experiment showcased that the charge on any oil droplet was a multiple of this value, emphasizing the quantized nature of electric charge and fundamental properties of electrons.

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Recent questions

  • What is the focus of Class 11th Chemistry Chapter Number Tu?

    The Structure of Atom

  • Who discovered the electron?

    Sir J Thomson

  • What experiment did Thomson conduct to observe electron behavior?

    Cathode experiment with metal plates

  • How was the charge on an electron determined in the Propane Oil Drop experiment?

    By observing the equilibrium of forces on oil droplets with electrons

  • What is the relative charge on an electron compared to a proton?

    -1

Related videos

Summary

00:00

Thomson's Discovery of Electron Charge Ratio

  • Welcome to Magnet Brains, a channel offering free quality education by Self Himmat.
  • The topic discussed is Class 11th Chemistry Chapter Number Tu, focusing on the Structure of Atom.
  • Sir J Thomson discovered the electron, leading to various experiments on the Discovery of Electron.
  • Thomson conducted the cathode experiment with metal plates to observe electron behavior.
  • Different discharge tubes with electrodes of various metals were used to study electron behavior.
  • Thomson calculated the charge by mass ratio of electrons to be 1.75 * 10^11 coulombs.
  • The experiment involved applying electric and magnetic fields to observe cathode ray behavior.
  • The cathode rays showed deviations due to the different metal plates used in the experiment.
  • Thomson calculated the charge by mass ratio by considering the intensity of bright spots and angles.
  • The charge by mass ratio of electrons was determined through the Thomson experiment.

15:30

Oil Drop Experiment Determines Electron Charge

  • Million Sir and Militant Sir conducted the Propane Oil Drop experiment to determine the charge on an electron.
  • The scientist who created the experiment was Malikanas, also known as Drop.
  • The experiment involved an atomizer to spray oil droplets of atom-sized particles.
  • Oil droplets were charged by colliding with high-frequency X-ray radiation.
  • The charged oil droplets were suspended between two metal plates, one blue and one red.
  • A light source and a microscope were used to observe the oil droplets.
  • The equilibrium of forces on the oil droplets with electrons determined the charge on them.
  • The charge on one electron was calculated to be 1.6 * 10^-19 coulombs.
  • The charge on any oil droplet was an integral multiple of this fixed value.
  • The charge of n electrons on an oil droplet was always a whole number multiple of the charge on one electron.

30:35

Charge of Electron: Key Formulas and Concepts

  • To find the charge on any body, use the formula k = integers integral multiple number.
  • The relative charge on an electron is -1, compared to a proton which has a positive charge.
  • The charge on an electron is -1.6 * 10^-19 Coulombs.
  • Thomson calculated the charge-to-mass ratio of an electron to be 1.75 * 10^11 Coulomb/K.
  • The mass of an electron is 9.1 * 10^-31 kg.
  • The mass of an electron is extremely small, not considered in atomic mass calculations.
  • Thomson's experiments determined the charge of an electron through mass ratios and Millieux's oil drop experiment found the charge of n electrons.
  • Understanding the charge by mass ratio, charge of an electron, and mass of an electron is crucial for exams and understanding electron properties.
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