1. Section 5: Radioactive Elements
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2. Radioactivity
The nuclei of some elements’ isotopes do not hold together well. So they release fast-moving particles and energy to become stable.
This process of releasing particles and energy is called radioactive decay.

3. Types of Radioactive Decay
During alpha decay, a nucleus loses an alpha particle, which consists of two protons and two neutrons.

4. Types of Radioactive Decay
During beta decay, a neutron inside an unstable nucleus changes into a negatively charged beta particle and a proton.

5. Types of Radioactive Decay
Gamma radiation has no charge and does not cause a change in either the atomic mass or the atomic number.

6. Types of Radioactive Decay
The three types of nuclear radiation were named based on how easily each one could be blocked. Alpha, beta, and gamma are the first three letters of the Greek alphabet.

7. Using Radioactive Isotopes
Tracers are radioactive isotopes that can be followed through the steps of a chemical reaction or industrial process.

8. Click the Video button to watch a movie about radiation.

9. End of Section: Radioactive Elements