Question

Why was it necessary to maintain a vacuum in the Rutherford experiment?

Answer 1

Rutherford experiment:

• Rutherford carried out an experiment in which he attacked a thin sheet of gold with $\mathrm{\alpha }$-particles and then tracked their path after striking with the gold foil.
• In his experiment, Rutherford focused on high-energy streams of $\mathrm{\alpha }$-particles from a radioactive source on a thin sheet of gold ($100\mathrm{nm}$ thickness). He draped a fluorescent zinc sulfide screen all around thin gold foil to study the deflection of the $\mathrm{\alpha }$-particles.
• Some of Rutherford's findings disputed Thomson's atomic idea.

The necessity of vacuum in Rutherford experiment:

• A positively charged helium ion comes into conflict with kinetic energy in the Rutherford experiment.
• The vacuum is important because any deflection of the alpha particles would only be because of collisions with the gold foil and not due to collisions with air particles.
• The positive charge and kinetic energy of the helium ion govern its influence on subatomic particles.
• The environment, whether air or another gaseous medium, will impede the movement of the helium ions, lowering their kinetic energy.
• Furthermore, because helium ions are positive, they may clash with the gaseous molecules, ionize them, and struggle to reach the gold foil at all.

As a result, establishing a vacuum in the chamber is critical for the helium ion to strike the gold foil.