Alpha decay (T7)

Question 1

What is the general form of the alpha decay equation?

Explain the process in steps.

Answer 1

Element X is turned into element Y by the emission of an alpha particle.

The alpha particle, a helium nucleus, carries away four nucleons, which reduces the mass number (A) by four.

Two of these nucleons are protons, so they atomic number of the new elements is two less than the original element (Z-2).

Note that the mass number and the atomic number are conserved through this equation - that is, the TOTAL numbers of nucleons and protons on each side of the equation are the same.

Question 2

Using the radioactive isotope radium-222 as an example, explain the process of alpha decay..

Answer 2

The radioactive isotope radium-222 decays to the element radon by the emission of an alpha particle.

Radon is a radioactive gas that also decays by emitting an alpha particle.

Note that the atomic number for radon, 86, is two less than the atomic number for radium.