Radioactivity

• Alpha decay is the emission of an alpha particle, which consists of two protons and two neutrons.
• Radiation therapy uses high energy gamma rays from cobalt-60 to destroy cancer cells.
• Radioisotopes are used as tracers, which can be detected by their radiation or chemical properties.
• Beta particles are electrons or positrons emitted by certain types of radioactive nuclei.
• The half-life is the time taken for one-half of the radioactive nuclei to decay.
• Alpha particles consist of two protons and two neutrons bound together, identical to helium nuclei.
• Neutron decay is the emission of a neutron from an unstable nucleus.
• Gamma rays are high-energy electromagnetic radiation emitted during nuclear reactions or decays.
• Nuclear fission occurs when a heavy nucleus splits into smaller fragments, releasing energy and producing radioactive products.
• Nuclear fission occurs when a heavy nucleus splits into smaller fragments, releasing large amounts of energy.
• Fusion reactions occur between light elements such as hydrogen and helium, resulting in the release of even more energy than nuclear fission.
• X-rays are similar to gamma rays but are produced artificially using machines like X-ray tubes.
• Nuclear fission occurs when a heavy nucleus splits into smaller fragments with the release of energy.
• What is ionisation?

  Process of making ions
• what is irradiation?

  When an object is exposed to ionising radiation but doesn't become radioactive.
• What safety precautions do you need to take with ionising radiation?

  gloves, tongs, keep alpha/beta/gamma pointed away from you, wear a lead lined apron, limit does and contact
• Why is ionising radiation dangerous?

  It can damage DNA in the nucleus and lead to mutation and cancer.
• What happens in alpha decay?

  Mass number decreases by 4, atomic number decreases by 2.
• What happens in gamma decay?


  Top and bottom stay the same - neautral mass and charge.
• What happens in beta decay?

  Mass number stays the same, atomic number increases by 1.
• What happens in an uncontrolled fission reaction?

  chain reaction - explosion
• What are some differences between nucleur fission and fusion?

  Fission - splitting of nuclei, needs a neutron bullet to start, happens in nucleur power, produces lots of energy, radioactive waste, no co2
• What are some key points in nucleur fusion?

  joining of nuclei, needs right conditions to start, happens in stars, produces even more energy, no harmful products
• What are tracers used for and why?

  Exploring internal organs - half life - 8 days, decays to stable product, gamma - can be detected outside the body.
• What is radiotherapy used for and why?

  Destroys cancerous cells, half life - 5 years, gamma
• What are gamma cameras used for and why?

  Takes images of internal organs, solution with gamma, decays to stable product.
• What is the unit for half life?

  Bequerel Bq
• What is a conventional power station?

  fossil fuels as source, burned to release heat energy to boil water
• What is a nucleur power station?

  Uranium (decay of this can be a chain reaction) as source - nucleur reaction takes place to create steam - nucleur fission
• How is a reaction in a nucleur reactor monitored and controlled?

  Control rods in core absorb surplus neutrons - keeps chain reaction under control - made from carbon because they absorb neutrons.