Electrons (The Sub-Atomic Particle) , Discovered the Electrons, Mass of Electrons (For CBSE, ICSE, IAS, NET, NRA 2022)

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Electrons and Compounds

  • Later, scientists discovered the fundamental sub-atomic particles protons, electrons, and neutrons. An atom has a bulk mass at its centre called a nucleus. The nucleus contains the protons and the neutrons.
  • Considering the solar system, it has been observed that the sun is at its centre, and the planets revolve around it. Similarly, in an atom, the nucleus is at the centre, and the electrons revolve around the nucleus.
Electron Structure

Electron structure

  • The above image clearly shows the structure of an atom and its similarity with the structure of the solar system. The planets in the case of solar system or electrons in the event if an atom revolves around the sun and the nucleus respectively.
  • The credit for the discovery of electron goes to J. J. Thompson. He performed an experiment on the cathode rays; he showed that the cathode rays are charged particles. The velocity of cathode rays was much less as compared to the speed of light. He devised methods to measure the charge to mass ratio of cathode rays. Thompson, therefore, concluded that the cathode rays are th mass of hydrogen ion (which is a proton) . These negatively charged cathode ray particles are now known as electrons.
  • Electrons are negatively charged particles with negligible mass. The mass of an atom is the sum of the number of protons and neutrons. Protons are positively charged particles whereas neutrons do not carry any charge. The number of protons and electrons is equal hence an atom is electrically neutral in nature. Protons and neutrons together are known as nucleons.

Questions

What is Electron Made Of?

Answer:

Electrons are fundamental particles so they cannot be decomposed into constituents. They are therefore not made or composed. An electron acts as a point charge and a point mass.

What is Electron and Proton?

Answer:

Electrons are a type of subatomic particle with a negative charge. Protons are a type of subatomic particle with a positive charge.

Why Do Electrons Have Charge?

Answer:

The electron gets its charge by coupling to the electromagnetic field. We think that the strength of this coupling must be such that it precisely cancels the other charges in its generation.

Who Decided Electrons Are Negative?

Answer:

Benjamin Franklin

  • Renaming electrons as positively charged would require renaming almost all the other charge carriers as negatively charged.
  • Such an action would probably make things less simple, not more. Benjamin Franklin was the one who first chose to call electrons negative and protons positive.

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