term,name,definition,category,provenance,provenance_uri,note radioactivity,Radioactivity,"Activity is the term used to characterise the number of nuclei which disintegrate in a radioactive substance per unit time. Activity is usually measured in Becquerels (Bq), where 1 Bq is 1 disintegration per second.",Quantum Mechanics,QUDT,http://qudt.org/vocab/quantity#Activity,