types of radiation

• The protons and neutrons form the nucleus in the centre of the atom and the electrons orbit the nucleus in their shells
• Isotopes of the same element have equal numbers of protons but different numbers of neutrons in their nuclei
• Radioactive decay occurs due to an imbalance between the number of protons and neutrons in a nucleus
• the nucleus will decay by emitting radiation to make the nucleus more stable
• There are three types of emissions:

  • alpha
  • beta
  • gamma
• Alpha emissions occur when a nucleus decays by emitting a helium nucleus, consisting of 2 protons and 2 neutrons
• Beta decay is where a neutron, in an unstable atom, changes to a proton and emits a high-energy electron
• Gamma emissions occur where a nucleus releases some energy in the form of an electromagnetic wave
• each of these types of radiation is ionising, which means they all have the potential to cause harm to living cells
• ionising radiation has the potential to remove an electron from an atom
• When ionising radiation occurs in the DNA molecule of a living cell, it can change the chemical properties of the atom and kill the cell or cause it to grow in an abnormal way
• radioactive decay is a random and spontaneous process
• an unstable nucleus will decay by emitting radiation, but it is possible to know when.
• The random nature of radioactive decay must be considered when taking mesurements
• most background radiation comes from natural sources
• there are some radioactive isotopes of many common elements in food and the materials used in building
• cosmic radiation travels through the atmosphere from space. this means background radiation will vary altitude as there is more cosmic radiation at higher altitudes
• Nuclear power stations and nuclear medicine produce radioactive waste materials, some of which remain radioactive for thousands of years
• background radiation is due to a low level of radioactive emissions occurring around us
• background varies due to cosmic radiation, rocks and radon
• background radiation is mostly due to artificial sources
• Alpha, beta and gamma have different properties
• alpha is the most ionising and gamma is the lease ionising
• Alpha is the least penetrating and gamma is the most penetrating
• each type of ionising radiation emitted during radioactive decay can cause damage to cells and even cancer, but they are not equally dangerous
• an alpha source outside the body is not very dangerous, despite being the most ionising
• alpha has a helium nucleus
• beta has a high-energy e;ectron
• gamma is electromagnetic wave