Year 12

Research assignment

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Industry Isotope 1. Americium–241 2. Uranium-237 + Helium-4 → plutonium-241
Plutonium-241 + electron → Americium-241 Americium is made by bombarding uranium or plutonium with neutrons in nuclear reactors 3. Americium is used in smoke alarms where it emits alpha particles and low energy gamma rays to form Neptunium – 237 4. When no smoke is present, the alpha particles ionise nitrogen and oxygen in the air in the detector. When smoke is present the smoke absorbs the alpha particles emitted so the rate of ionisation drops and this sets of the alarm. 5. Out of date or damaged smoke detectors must be sent back to the manufactures as the americium in the smoke detectors is harmful if inhaled. The americium will then be taken out of the smoke detectors and stored in a nuclear waste disposal facility. 6. Benefits: a. Allows the operation of smoke detectors that can warn people when a fire is starting and thus save lives and property. 7. Problems: a. Radiation can affect the structure of enzymes so they cannot act as catalysts. b. The structure of membranes can be changed, this presenting transport within and between cells. c. Alpha radiation causes damage to cells on contact or when or very close, but has little ability to penetrate.

Medicine Isotope 1. Cobalt – 60 2. Cobalt – 59 + neutron = Cobalt 60 →nickel 60 + gamma rays 3. The main use of cobalt 60: some