Topic 5 - Types of Radiation

• What is the nucleon number, proton number and the number of neutrons of the following nuclei?

  O₈¹⁶ - proton number is 8, nucleon number is 16, amount of neutrons = 16-8 = 8, this is not radioactive as it is balanced.

  U₉₂²³⁸ - proton number is 8, nucleon number is 238, amount of neutrons = 238-92 = 148, this is not balanced and so it is radioactive.
• What is an isotope?

  2 similar elements with the same proton number and different amount of neutrons.
• Why are some nuclei radioactive and some aren't?

  Some have equal protons to neutrons, they are balanced and not radioactive.
• Why must experiments using radioactive sources to be done for long periods of time and repeated?

  Radiation is random.
• Why is radioactive waste dangerous and expensive to dispose of?

  It is ionising (causes cell mutation - cancer), stored underground cased in lead to stop beta and alpha and reduce gamma - it also has a long half life so has to be stored for 1000s of years.
• What is background radiation?

  Harmless low levels of radiation in the air around us.
• What are the main parts of background radiation?

  Nuclear power stations, buildings, radon gas (50%), food and drink, cosmic rays, hospitals.
• How does radiation get into food and drink?

  Plants/animals are outside exposed to background radiation. Plants are grown in the ground which contains radon gas, animals eat the plants that contain radon gas.
• What is radon gas?

  Gas contained in the Earth inside rocks, depends on the rocks underground, some areas are high (Wales) some are low (England).
• What does 'correcting for background radiation' mean and how do you do it?

  To do it you take away background from all your readings.
• What are the 3 types of radiation?

  Alpha, Beta, Gamma.
• What are the three types of radiation stopped by?

  Paper stops alpha, aluminium stops beta, gamma is reduced by thick lead or concrete.
• What is an alpha emitter?


  Helium nucleus
• What is a beta emitter?


  Fast moving electrons.
• Why is alpha radiation dangerous when ingested?

  Because it can't pass through skin, it is also the most ionising.
• Why is beta the most dangerous outside the body?

  Most penetrating, it can easily pass into your body.
• What is the symbol for alpha?

  
• What is the symbol for beta?

  
• What is the symbol for gamma?