1 / 15

Chapter 2 Nuclear physics (Chap. 30 page 745)

Chapter 2 Nuclear physics (Chap. 30 page 745). Dr. Haykel Abdelhamid Elabidi. February 2014/3 rd week of RaT 1435. Units of Chapter 30. Introduction Radioactivity Half-life. Introduction. History of Radioactivity.

aya
Télécharger la présentation

Chapter 2 Nuclear physics (Chap. 30 page 745)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 2 Nuclear physics(Chap. 30 page 745) Dr. Haykel Abdelhamid Elabidi February 2014/3rd week of RaT 1435

  2. Units of Chapter 30 • Introduction • Radioactivity • Half-life

  3. Introduction

  4. History of Radioactivity • Antoine Henri Becquerel (1852-1908) noted that uranium compounds produce invisible rays or radiation that can penetrate an opaque container. • Pierre and Marie Curie showed that uranium ores contain traces of polonium (A=84) and radium (Z=88), both much more intensely radiative than uranium.

  5. History of Radioactivity

  6. Note: This is theatomic weight, whichis the number ofprotons plus neutrons Alpha Particles (a) Example of nuclear reactions: Uranium U238 Thorium Th234 p + n n p a (4He) 92 protons 146 neutrons 90 protons 144 neutrons 2 protons 2 neutrons

  7. Beta Particles (b) Carbon C14 Nitrogen N14 + e- electron (beta-particle) 6 protons 8 neutrons 7 protons 7 neutrons We see that one of the neutrons from the C14 nucleus “converted” into a proton, and an electron was ejected. The remaining nucleus contains 7p and 7n, which is a nitrogen nucleus. In symbolic notation, the following process occurred: n  p + e ( + n ) - faster than alpha particles, penetrate light materials, 10 mm of wood, 3 mm of Al

  8. Gamma particles (g)Gamma rays are high-frequency electromagnetic radiations (i.e. photons) which do not carry any charge. A nucleus can be in an excited state, as electrons in the atom. Neon Ne20 Neon Ne20 + 10 protons 10 neutrons(lowest energy state) gamma 10 protons 10 neutrons(in excited state) • very fast and able to penetrate most materials such a 7 cm of lead • can be harmful to our bodies, suffer structural damage • - It is NOT visible by your naked eye because it is not in the visible part of the EM spectrum.

  9. Half-life (T)

  10. Half-life (T)

  11. Half-life (T)

  12. Half-life (T) Solution Example 30.1 page 747:

  13. Effective half-life

  14. Effective half-life Solution Example 30.2 page 748:

  15. Homeworks: Exercises 30.1; 30.2; 30.3; 30.5; 30.7 page 762 Thank you for your attention See you next time Inchallah

More Related