1 / 12

Nuclear Chemistry

Nuclear Chemistry. September 21, 2009 Trianna McCall. Nuclear Reactions. Nuclear chemistry is the study of changes in an atoms nucleus. Reactions that involve a change in the nucleus of an atom are called nuclear reactions . Characteristics of Nuclear Reactions.

tryna
Download Presentation

Nuclear Chemistry

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. Nuclear Chemistry September 21, 2009 Trianna McCall

  2. Nuclear Reactions • Nuclear chemistry is the study of changes in an atoms nucleus. • Reactions that involve a change in the nucleus of an atom are called nuclear reactions.

  3. Characteristics of Nuclear Reactions • Occur when nuclei emit particles and/or rays • Atoms are often converted into atoms of another element • May involve protons, neutrons, and electrons • Associated with large energy changes • Reaction rates aren’t normally affected by temperature, pressure, or catalyst Table 25-1 (p805 of textbook)

  4. What Causes Nuclear Reactions? • The nuclei of some atoms are unstable and may undergo several changes. • Unstable systems gain stability by losing energy. • Certain atoms lose energy by emitting rays and particles called radiation.

  5. Related Terms • This spontaneous emission of radiation is a process called radioactivity. • The process by which unstable nuclei emit radiation to lose energy is called radioactive decay. • Radioisotopes, isotopes of atoms with unstable nuclei, undergo nuclear decay.

  6. Types of Radiation • Alpha -Composed of alpha particles -Contains 2p+ and 2n⁰ -42He • Beta -Composed of beta particles -Fast moving e- - 0-1β or 0-1e

  7. Types of Radiation (cont) • Gamma -Not deflected by electric or magnetic fields -No charge -00γ • http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/radioa7.swf

  8. Types of Radiation Summary

  9. Nuclear Equations • Used to express nuclear reactions • Both sides of the equation must have an equal sum of atomic mass and atomic numbers • Examples: - 23592U  ______________ + 23190Th - 37K  0e + ______________ - 41Ca  Ca + 0 _________________

  10. Half-Life • The time required for one half of a radioisotope’s nuclei to decay into its products is called a half-life. • Amt Remaining=(Initial Amt)(1/2)n -n = # half lives passed • Amt Remaining=(Initial Amt)(1/2)t/T -t=elapsed time -T=duration of half life

  11. Half-Life (cont) • Example half-life problems: - How much of a 100.0g sample of 198Au is left after 8.10 days if its half-life is 2.70 days? -A 50.0g sample of 16N decays to 12.5g in 14.4 seconds. What is its half-life? -The half-life of 42K is 12.4hours. How much of a 750g sample is left after 62.0hours? -What is the half-life of 99Tc if a 500g sample decays to 62.5 g in 639,000 years?

  12. Fission and Fusion • The splitting of an atoms nucleus into fragments is called fission. -Provides energy for nuclear power plants • http://www.visionlearning.com/library/flash_viewer.php?oid=2391&mid=59 • The combining of atomic nuclei is called fusion. -Fuels the sun • http://www.visionlearning.com/library/flash_viewer.php?oid=2747&mid=59

More Related