Question

Alpha rays consist of a stream of:
(A) ${{H}^{+}}$
(B) $H{{e}^{2+}}$
(C) Only electrons
(D) Only neutrons

Answer 1

Hint: The composite alpha particle ($\alpha $) is made up of two protons and two neutrons that are firmly bonded together. They are released from the nucleus of some radionuclide during an alpha-decay process, a kind of radioactive decay. The alpha particles are emitted when a radioactive element undergoes alpha decay. The alpha ray has a mass of$6.6466\times {{10}^{-27}}Kg$.

Complete step by step solution:
An alpha particle is a helium nucleus without electrons ($H{{e}^{2+}}$). It is a positively charged particle. The alpha rays have low penetration power. It cannot even penetrate a sheet of paper or the outer layer of human skin. Thus, it poses no danger to the human body.

The alpha particles are heavy particles and thus move very slowly as compared to the speed of light. Energy from the radiation is transmitted from the alpha particles to the atoms or molecules that make up the substance as they travel through it.
Correct Option: (B)$H{{e}^{2+}}$.

Additional Information: British physicist Ernest Rutherford discovered that radioactive substances emit three separate types of radiation, which he named alpha, beta, and gamma rays. Alpha particles are the heaviest particles among all three types of rays.

Note: The alpha rays have the power to ionise a large number of atoms at a close range. It's because handling radioactive materials that emit alpha particles requires the use of rubber gloves first.