Radiation Exposure When an atomic nucleus releases a radioactive particle, one radioactive count occurs. Non-radioactive substances don’t ever release any counts, so the important measurement is how many counts per second a substance releases. This activity is given the SI unit called the becquerel ( Bq ). An older unit called the curie ( Ci ) is often still used and is equal to 37 billion becquerels. Obviously, the larger the sample of a given radioactive substance, the more counts per second it will release. Still, rather than dealing with the natural radioactive density of a material in Bq/m ³ and then multiplying by the volume, a lab will simply specify the size of the sample in becquerels or curies. Not all substances ejecting the same radioactive particle give it the same average energy, however. In order to gauge the damage to mammalian tissue by radiation, the unit called the sievert ( Sv ) was devised. This unit attempts to predict the average amount of energy delivered in
This is the end of the preview.
access the rest of the document.