Radioactive Decay Cards

Super Value Game


Determine the natural decay of uranium–238 by arranging element cards and radioactive particles to create the uranium-238 decay series.


  • Radioactive decay
  • Beta particle
  • Alpha particle
  • Half-life


Nuclear stability and radioactive decay are important concepts to understanding nuclear chemistry, the size of the nucleus, and the energy that holds it together. Radioactive decay also plays an important role in society in the form of energy, medical tracers and weapons. The radioactive decay of uranium isotopes has been extensively studied due to its abundance in nature and the important role uranium plays in nuclear power and weapons. The uranium–238 isotope is the predominant species (99.3%) found in nature and undergoes a slow radioactive decay to lead–206. Natural uranium also contains 0.7% of uranium–235. When bombarded with neutrons, uranium-235 will undergo nuclear fission and break into two lighter elements, releasing substantial amounts of energy. This is the principle behind the nuclear power industry and nuclear weapons.

Most textbooks have at least one chapter devoted to Nuclear Chemistry. Several important terms will be clarified here and should be understood prior to beginning the activity.

A Nuclide is a unique atom, represented by the symbol

where X is the symbol for the element, A is the mass number or total number of neutrons and protons and Z is the atomic number or the total number of protons in the nucleus.

A Beta Particle (β) is an electron produced in a radioactive decay. The β-particle is represented as
It has no mass and a charge of –1. β-particle production is the most common type of decay and the net effect is to change a neutron into a proton. During β-particle decay, the mass of the nuclide stays the same but the atomic number increases by one and a new element is produced. This is the process that occurs during the radioactive decay of carbon–14.
An Alpha Particle (α) is a helium atom produced during radioactive decay. α-particle production is a very common mode of decay for heavy radioactive isotopes and is represented by
The net result is the loss of two neutrons and two protons from the nucleus and subsequently a smaller atomic number (–2) and mass number (–4).
A Half-Life (t½) is described as the time required for one-half of the nuclides to undergo radioactive decay. It is a constant for each radioactive nuclide.

The splitting of a heavy nucleus by a neutron into two lighter nuclei, accompanied by a large release of energy in known as nuclear fission.

Experiment Overview

In this activity, the order of natural decay of a radioactive element (U–238) to a stable species (Pb–206) must be determined. There will be thirteen (13) nuclide species between U–238 and Pb–206. Each radioactive decay will emit an alpha or beta particle.


Graph paper
Radioactive Decay Series cards, 6 packages*†
*Materials included in kit.
Each package has 15 elements, 6 beta particles and 8 alpha particle cards.


  1. Arrange the element cards in order of the natural radioactive decay with either an alpha or beta particle between each element.
  2. After putting the cards in order, make a graph of mass number (y-axis) vs. atomic number (x-axis) for each element in the series. Write the element’s symbol at its point on the graph and connect the appropriate points in order of decay with an arrow.
  3. Finally, give one example each for an alpha decay equation and a beta decay equation from the graph.

Correlation to Next Generation Science Standards (NGSS)

Science & Engineering Practices

Asking questions and defining problems
Developing and using models
Analyzing and interpreting data
Using mathematics and computational thinking

Disciplinary Core Ideas

MS-PS1.A: Structure and Properties of Matter
MS-PS3.B: Conservation of Energy and Energy Transfer
HS-PS1.C: Nuclear Processes
HS-PS1.A: Structure and Properties of Matter
HS-PS2.B: Types of Interactions
HS-ETS1.C: Optimizing the Design Solution

Crosscutting Concepts

Systems and system models
Energy and matter
Stability and change

Performance Expectations

HS-PS1-8. Develop models to illustrate the changes in the composition of the nucleus of the atom and the energy released during the processes of fission, fusion, and radioactive decay.
HS-PS4-3. Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model, and that for some situations one model is more useful than the other.
MS-PS1-1. Develop models to describe the atomic composition of simple molecules and extended structures.


Special thanks to Steven Purkis, Charles Sumprer, Kirstin Distante and Brian Adler at Tappan Zee High School, Orangeburg, NY, for providing us with the idea and instructions for this activity.

ChemCom, Chemistry in the Community, 3rd ed; Kendall/Hunt: Dubuque, IA, 1996; Unit 5.

Purkis, S.; Sumprer, C; Distante, K., Adler, B. Chem 13 News, April 1997, p 19.

Zumdahl, S. S. Chemistry, 4th ed: Houghton Mifflin: New York, 1997; Chapter 20.

Next Generation Science Standards and NGSS are registered trademarks of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of this product, and do not endorse it.