nuclear chemistry. chemical vs. nuclear reactions chemical reactions involve valence electrons and...
Post on 26-Mar-2015
Embed Size (px)
- Slide 1
Nuclear Chemistry Slide 2 Chemical vs. Nuclear Reactions Chemical reactions involve valence electrons and atoms bonding together. Nuclear Reactions involve the nucleus of atoms. Slide 3 What makes an atom stable? Proton to Neutron Ratio is just right. Strong Nuclear Force is what holds the nucleus together Slide 4 What is Radioactivity? Atoms with unstable nuclei cause radioactivity. The proton to neutron ratio is not balanced, so the strong force doesnt hold the nucleus together. The unstable nuclei breaks into smaller (more stable) atoms and release energy. Slide 5 Here is a picture! Slide 6 Nuclear Fission Reactions Occur spontaneously Occur in atoms with more than 83 protons Emit radiation- particles with energy Slide 7 Types of Radiation Alpha particles 2 protons, 2 neutrons Helium nucleus 2+ charge Beta Particle similar to an electron 1- charge No mass Gamma ray no mass no charge high energy Slide 8 How powerful are these particles? Slide 9 Nuclear Decay Reactions 1.Write the parent isotope on the left side of the arrow. 2.Place the emission particle (what is lost) on the right side of the arrow. 3.Place the daughter isotope on the right side of the arrow. Slide 10 Example Uranium-238 decays by emitting an alpha particle to form thorium-234. 238 92 U 234 90 Th + 4 2 He Slide 11 Now you try! Potassium-40 decays to calcium-40 by beta emission. 40 19 K 40 20 Ca + 0 -1 Slide 12 Practice Nuclear Reaction Problems Write the equation for the beta emission by Ni-59. Write the equation for the alpha emission by Ra-226. Slide 13 Nuclear Fusion Small atoms are brought together to form a larger atom. Process that occurs on the sunprovides a lot of energy. Slide 14 Why is it important? Slide 15 Nuclear Medicine Radioactive isotopes are injected or ingested. Detectors see the particles and can provide an image that help doctors diagnose problems. Can also be used to treat conditions such as cancer.