We now know that α particles are high-energy helium nuclei, β particles are high-energy electrons, and γ radiation compose high-energy electromagnetic radiation. Types of Radioactive DecayĮrnest Rutherford’s experiments involving the interaction of radiation with a magnetic or electric field ( Figure 2) helped him determine that one type of radiation consisted of positively charged and relatively massive α particles a second type was made up of negatively charged and much less massive β particles and a third was uncharged electromagnetic waves, γ rays. Click here to learn about cloud chambers and to view an interesting Cloud Chamber Demonstration from the Jefferson Lab. The alpha particle removes two protons (green) and two neutrons (gray) from the uranium-238 nucleus.Īlthough the radioactive decay of a nucleus is too small to see with the naked eye, we can indirectly view radioactive decay in an environment called a cloud chamber. A nucleus of uranium-238 (the parent nuclide) undergoes α decay to form thorium-234 (the daughter nuclide). The radiation produced during radioactive decay is such that the daughter nuclide lies closer to the band of stability than the parent nuclide, so the location of a nuclide relative to the band of stability can serve as a guide to the kind of decay it will undergo ( Figure 1). The daughter nuclide may be stable, or it may decay itself. The unstable nuclide is called the parent nuclide the nuclide that results from the decay is known as the daughter nuclide. The spontaneous change of an unstable nuclide into another is radioactive decay. During the beginning of the twentieth century, many radioactive substances were discovered, the properties of radiation were investigated and quantified, and a solid understanding of radiation and nuclear decay was developed. Among them were Marie Curie (the first woman to win a Nobel Prize, and the only person to win two Nobel Prizes in different sciences-chemistry and physics), who was the first to coin the term “radioactivity,” and Ernest Rutherford (of gold foil experiment fame), who investigated and named three of the most common types of radiation.
Describe common radiometric dating techniquesįollowing the somewhat serendipitous discovery of radioactivity by Becquerel, many prominent scientists began to investigate this new, intriguing phenomenon.Calculate kinetic parameters for decay processes, including half-life.Write and balance nuclear decay equations.Identify common particles and energies involved in nuclear decay reactions.Recognize common modes of radioactive decay.
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