Skip to main content
Ch.21 - Nuclear Chemistry
Chapter 21, Problem 15

Decay of which nucleus will lead to the following products: radium-226 by alpha decay?

Verified step by step guidance
1
Understand that alpha decay involves the emission of an alpha particle, which consists of 2 protons and 2 neutrons. This means the atomic number decreases by 2 and the mass number decreases by 4.
Identify the original nucleus: radium-226. Its atomic number is 88 (Ra) and its mass number is 226.
Apply the changes due to alpha decay: Subtract 2 from the atomic number (88 - 2) and 4 from the mass number (226 - 4).
Determine the new element: The new atomic number is 86, which corresponds to the element radon (Rn) on the periodic table.
Conclude that the decay of radium-226 by alpha decay results in the formation of radon-222.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Alpha Decay

Alpha decay is a type of radioactive decay in which an unstable nucleus emits an alpha particle, consisting of two protons and two neutrons. This process reduces the atomic number of the original nucleus by two and the mass number by four, resulting in the formation of a new element. For example, when uranium-238 undergoes alpha decay, it transforms into thorium-234.
Recommended video:

Nuclear Reactions

Nuclear reactions involve changes in an atom's nucleus and can result in the transformation of one element into another. These reactions can be induced by various means, including radioactive decay, fission, and fusion. Understanding the principles of nuclear reactions is essential for predicting the products formed during decay processes.
Recommended video:
Guided course
02:06
Nuclear Binding Energy

Radium-226

Radium-226 is a radioactive isotope of radium that is commonly produced through the decay of uranium and thorium. It has a half-life of about 1600 years and undergoes alpha decay to form radon-222. Identifying the parent nucleus that decays to radium-226 is crucial for understanding its origin and the decay chain it belongs to.
Recommended video:
Guided course
01:22
Alpha Decay Reaction Example