1. Notes 4-5 Radioactive Elements

2. Isotopes Atoms with same number of protons but different numbers of neutrons Example: Carbon-12 (normal carbon) versus Carbon-14 Some isotopes are unstable Nuclei break down in a process of radioactive decay, releasing particles and energy

3. Radioactivity Radioactivity is the spontaneous emission of radiation. Example: Uranium, Polonium, Radium Henri Becquerel discovered the effects of radioactive decay by accident while studying a mineral that contained uranium. There are 3 types of radioactive decay

4. Types of Radioactive Decay During alpha decay, a nucleus loses an alpha particle, which consists of two protons and two neutrons. * Decreases atomic # by 2, and mass # by 4

5. Types of Radioactive Decay During beta decay, a neutron inside an unstable nucleus changes into a negatively charged beta particle and a proton. * Atomic # increases by 1, mass # remains the same

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

7. 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.

8. Tracers Tracers are radioactive isotopes that can be followed through the steps of a chemical reaction or an industrial process. Turn to page 162 in your textbook and review how Phosphorus-32 is absorbed by plant roots so that biologists can learn where and how plants use phosphorus. In industry, tracers can be used to find weak spots in metal pipes.

9. Using Radioactive Isotopes Cancer treatment Chemical reactions Industrial processes Electricity Smoke detectors Pest control Rock/ fossil dating Food treatment Nuclear weapons

10. Risks of Radioactive Isotopes Burn causing Cancer causing Genetic mutations death

11. Review Use your periodic table to predict the element that forms in each case of radioactive decay: IsotopeType of DecayElement Formed Uranium-238Alpha Nickel-63Beta Iodine-131Beta Radium-226Alpha Thorium-234 Copper-63 Xenon-131 Radon-222