Radioactivity and Decay PDF

RADIOACTIVITY and DECAY  Unstable atoms are radionuclides: they disintegrate into something stable. 3 main decay sequences are Alpha decay Β- and β+ decay...

RADIOACTIVITY and DECAY  Unstable atoms are radionuclides: they disintegrate into something stable. 3 main decay sequences are Alpha decay Β- and β+ decay ϒ decay 1. The only difference between x-rays and gamma rays is their ________. 2. The ________ is the least penetrating form of particulate ionizing radiation 3. A beta particle comes from ______________  HALF LIFE (how long must you wait before a radionuclide decays) When does a radionuclide decay? No one knows…. IMMEDIATELY or NEVER…. But if you start with a LARGE sample….. After a given period of time, ½ of the radionuclides have decayed The amount of time is unique to each radionuclide and is called the ½ life The amount of a radioactive substance Is measured in ACTIVITY The SI unit for Activity is the Becquerel (Bq) 1 Bq = 1 distintegration/second An older unit for Activity is the Curie (Ci) 1Ci = 3.7x1010Bq Convert 300 µCi to MBq Convert 1.2GBq to mCi Answer: 11.1 MBq 32.4 mCi 60Co has a half life of 5.27yrs. 3 half-lives is how many years? How many half-lives is 25 yrs? Starting with 32MBq of 60Co Estimate the activity after 2.635 yrs? Estimate the activity after 26.35 yrs?