Becquerel

Becquerel [ bɛkə'rɛl ], abbreviated Bq, is the SI unit of activity (symbol A) an amount of a radioactive substance. The activity indicates the mean number of nuclei that decay radioactively per second:

In daily use, the unit is almost always the use of a header of the magnitude necessary (especially kilo, mega and Tera ).

The unit is named after the French physicist Antoine Henri Becquerel, who along with Pierre Curie and Marie Curie was awarded the 1903 Nobel Prize for the discovery of radioactivity. The Becquerel was established in 1975 at the 15th meeting of the Conférence Générale des Poids et Mesures as SI derived unit with a particular name in the International System of Units.

Context

About the dose conversion factor to estimate the dose equivalent from the activity is possible. Articles radiation damage and radiation exposure limits are found, how they are specified, for example in food.

For a given mass (in grams) of an isotope with an atomic mass (in g / mol) and a half-life of ( in s), the radioactivity can be calculated with the following formula:

It is = 6.022 141 79 (30 ) · 1023 mol -1 is Avogadro's constant.

Example: potassium naturally contains 0.012 percent, or 0.12 grams per kilogram of the radioactive isotope 40K with a half -life of 1.248 · 109 years = 39.38388 · 1015 seconds, and has an atomic mass of = 39.96399848 g / mol. This results in a (radio ) activity of A = 31.825 kBq for a kilogram of natural potassium. At this relatively high translucent activity of a common element is taken into account that 40K is indeed the main source of natural radioactivity in organisms. For example, the potassium contained in the human body responsible for activity of about 5000 cps.

Other units

The unit becquerel replaced in the SI system the old unit for the activity - the Curie. The following relationship exists between these two units:

In addition, the following relationship applies:

The units Rutherford and Stat are more outdated non- SI -compliant units for the activity.