1 / 14

Bell Work

Bell Work. Is all radiation bad? Justify your answer. What is a fissure? What does it mean to fuse something together? What is a chain reaction? What are some uses of radiation that you can think of? Update your scientist timeline paper with Henri Becquerel and Pierre and Marie Curie.

maxine-lester
Download Presentation

Bell Work

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. Bell Work • Is all radiation bad? Justify your answer. • What is a fissure? • What does it mean to fuse something together? • What is a chain reaction? • What are some uses of radiation that you can think of? • Update your scientist timeline paper with Henri Becquerel and Pierre and Marie Curie

  2. Questions?

  3. Reality Check • ½ sheet of paper • Extra credit if you can tell me : • The type of radioactive particle • Was it emitted or captured?

  4. Uses of Radioactivity

  5. Nuclear Fission • The splitting of the nucleus of a large atom into two or more fragments • It produces additional neutrons and lots of energy • Fission can cause chain reactions – a reaction in which a change in a single molecule makes many molecules change. • Critical Mass – the minimum mass of a fissionable isotope that provides enough neutrons to maintain a chain reaction

  6. Figure 11 on page 654

  7. Chain Reactions are used in Nuclear Reactors

  8. Nuclear Fusion • The combination of the nuclei of small atoms to form a larger nucleus • This process also creates energy. • The sun uses nuclear fusion to generate heat and light.

  9. Half-Life and Geologic Dating • Half-life is the time required for half of a sample of radioactive substance to disintegrate by radioactive decay or natural processes. • So every time the “half-life time” passes, half of the parent substance (original substance) has turned into the daughter substance (new substance)

  10. Example ProblemsAmount remaining = Amount original (1/2) Total Time/Half Life • The half-life of polonium is 3.0 minutes. If you start with 16 mg of polonium-218, how much time must pass for only 1.0 mg to remain. • The half-life of radon-222 is 3.824 days. How much time must pass for one-fourth of a given amount of radon to remain. • Assuming a half life of 1599 years, how much radium will remain after 9594 years if the original amount was 900 grams? • What is the half life of a material if 1/8 of the material remains after 16 years?

  11. Geologic Dating • As you can guess, we can use half-life and radioactive decay to determine the geologic age of materials. • Example: An ancient artifact is found to have a ratio of carbon-14 to carbon-12 that is one-eighth of the ratio of carbon-14 to carbon-12 found in a similar object today. How old id this artifact? (C-14 has a half life of 5715 years).

  12. Other uses of Nuclear Chemistry • Smoke Detectors • Art Forgeries • Medicinal Reasons • X-rays • PET scans (Positron Emission Tomography)

  13. Even though radiation can be helpful, it can be dangerous • Large doses of radiation in a short period of time or small doses of radiation over long periods of time can lead to: • Decrease in white blood cells • Nausea • Loss of hair • Ulcers • Internal bleeding • Death

  14. Homework • Page 670: 37-42

More Related