Radioactivity- physics

• Nuclear radiation cannot make a stable isotope unstable
• The half life of an element can be measured by counting the number of decays per second
• A radioisotope with a short half life will have more decays than one with a long half life at any given moment in time.
• Cancer and sterilisation both invoke killing unwanted cells, but diagnosis used gamma rays to locate radioactive isotopes
• The longer someone is exposed to radiation, the greater the risk of cancer
• If the nuclei are more stable, they will decay less frequently so the half life will be longer
• Radiation from nuclear power stations is not dangerous as it is absorbed by the atmosphere or shielded by walls
• Lead is used for the storage of radioactive sources because it is very dense, and can block alpha and beta radiation and most of gamma radiation emitted by the sources.
• Radiatiin from outer space and is called cosmic radiation
• lonising radiation can damage the DNA in your cells, which can cause cancer, but it can also be targeted in such a way to kill cancerous cells and prevent tumors from growing.
• Radioisotopes have many uses including medical imaging, treating cancer, dating fossils, and detecting leaks in pipes
• Nuclear fission occurs when an atom splits into two smaller atoms releasing energy