1. 9.2 Nuclear Fission and Fusion I CAN: -RECOGNIZE THAT THE STRONG NUCLEAR FORCE IS THE ATTRACTIVE FORCE THAT BINDS PROTONS AND NEUTRONS TOGETHER IN THE NUCLEUS. -RECOGNIZE THAT WHILE THE NUCLEAR FORCE IS EXTREMELY WEAK AT MOST DISTANCES, OVER THE VERY SHORT DISTANCES PRESENT IN THE NUCLEUS THE FORCE IS GREATER THAN THE REPULSIVE ELECTRICAL FORCES AMONG PROTONS. -RECOGNIZE THAT WHEN THE ATTRACTIVE NUCLEAR FORCES AND REPULSIVE ELECTRICAL FORCES IN THE NUCLEUS ARE NOT BALANCED, THE NUCLEUS IS UNSTABLE. -COMPARE AND CONTRAST THE PROCESSES BY WHICH ENERGY IS CREATED DURING NUCLEAR FUSION AND FISSION

2. Nuclear Forces  Carbon-12 v. Carbon-14  Stability depends on nuclear forces that hold nucleus together.  Should protons repel each other?  Attraction due to strong nuclear force occurs over a very short distance.  3 x 10 -15 (3 protons)  Nuclear force and strong than repulsive force.

3. Make sure to have the following defined in your webquest  Fission  Mass-Energy Equation  E=mc 2  C= 3.0 x 10 8  Energy = 22 million tons of TNT  Nuclear chain reaction  Critical mass: minimum mass of fissionable isotope that provides the number of neutrons needed to sustain a chain reaction.  Fusion

4. 9.3 Nuclear Radiation Today I CAN: -RECOGNIZE RADIOACTIVE ISOTOPES HAVE SEVERAL MEDICAL APPLICATIONS AND THAT THE RADIATION THEY RELEASE CAN BE USED TO KILL UNDESIRED CELLS (E.G., CANCER CELLS). -RECOGNIZE THAT RADIOISOTOPES CAN BE INTRODUCED INTO THE BODY TO SHOW THE FLOW OF MATERIALS IN BIOLOGICAL PROCESSES

5. Where is radiation  Background radiation: the nuclear radiation that arises naturally from cosmic rays and from radioactive isotopes in the soil and air.  Tissue has adapted to survive this.  Rems: quantity of ionizing radiation that does as much damage to human tissue has as 1 roentgen of high voltage X-ray does.  1 rem=1000 mrem  Occupational safety= 5000 mrem

6. Some activities add to the amount of nuclear radiation exposure.

7. Beneficial Uses of Nuclear Radiation.  Smoke detectors  CTs, MRIs, X-Rays  Radioactive Tracers: radioactive material that is added to a substance so that its distribution can be detected later.  Short lived isotopes (locate tumors)

8. Nuclear radiation therapy to used to treat cancer  Brain tumors can be targeted with small beams of gamma rays. (kills damaged material and then new healthy material grows)

9. Other uses (Agriculture)  Radioactive tracers: track how fast water moves through soil or through stems and leaves of crops.

10. Nuclear waste must be safely stored.  Ideal places are far away from groundwater and in earthquake free zones. (used fuel rods)  Yucca Mountains, Nevada.  https://www.youtube.com/watch?v=iv0Mivu-ceE https://www.youtube.com/watch?v=iv0Mivu-ceE  https://www.youtube.com/watch?v=6rLjNvWzbZc https://www.youtube.com/watch?v=6rLjNvWzbZc