7Radioactivity - B.pdf
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Radioactivity – BookB Definitions Radioactivity is defined as the spontaneous breaking up of certain unstable nuclei, accompanied by the emission of radiation. Isotopes are elements with the same atomic number but di erent mass number. The half life of a radioactive isotope is the time taken for...
Radioactivity – BookB Definitions Radioactivity is defined as the spontaneous breaking up of certain unstable nuclei, accompanied by the emission of radiation. Isotopes are elements with the same atomic number but di erent mass number. The half life of a radioactive isotope is the time taken for half the atoms in a sample of the isotope to decay. Facts pioneered by Henri Becquerel Marie & Pierre Curie continued this work by discovering polonium & radium. A Geiger-Muller tube is used to detect radiation. Nuclear reactions result in elements changing into other elements Example: Carbon 14 decaying to form Nitrogen When an isotope undergoes beta emission: Atomic number increases by 1 Mass number remains the same When an isotope undergoes alpha decay: Atomic number decreases by 2 Mass number decreases by 4 Uses of Radioisotopes – Archaeology: Carbon-14 Medicine: Cobalt-60 , cancer treatment Smoke Alarms: Americium-241
