1. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 9 Nuclear Radiation 9.1 Natural Radioactivity 1

2. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Stable and Radioactive Isotopes A radioactive isotope has an unstable nucleus emits radiation to become more stable, changing the composition of the nucleus is identified by the mass number of the isotope 2

3. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Nuclear Radiation Nuclear radiation is the radiation emitted by an unstable atom and takes the form of alpha particles, neutrons, beta particles, positrons, or gamma rays. 3

4. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Types of Radiation Alpha (  ) particle is two protons and two neutrons. Beta (  ) particle is a high-energy electron. Positron (  + ) is a positive electron. Gamma rays are the high-energy radiation released from a nucleus when it decays. 4

5. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Give the name and symbol for the following types of radiation. A.alpha radiation B.radiation with a mass number of 0 and atomic number of +1 C.radiation that represents high-energy radiation released from the nucleus 5

6. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Give the name and symbol for the following types of radiation. A.alpha radiation B.radiation with a mass number of 0 and atomic number of +1 C.radiation that represents high-energy radiation released from the nucleus 6

7. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Radiation Protection Radiation protection requires paper and clothing for alpha particles a lab coat or gloves for beta particles a lead shield or a thick concrete wall for gamma rays limiting the amount of time spent near a radioactive source increasing distance from the source 7

8. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Shielding for Radiation Protection 8

9. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check What type of radiation will be blocked by A. lead shield B. paper, clothing 9

10. Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution What type of radiation will be blocked by A. lead shieldgamma radiation B. paper, clothingalpha radiation 10