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It was originally defined as "the quantity or mass of radium emanation in equilibrium with one gram of radium (element)", [1] but is currently defined as 1 Ci = 3.7 × 10 10 decays per second [4] after more accurate measurements of the activity of 226 Ra (which has a specific activity of 3.66 × 10 10 Bq/g [5]).
Disintegrations per minute (dpm) and disintegrations per second (dps) are measures of the activity of the source of radioactivity. The SI unit of radioactivity, the becquerel (Bq), is equivalent to one disintegration per second. This unit should not be confused with cps, which is the number of counts received by an instrument from the source.
Surface contamination is usually expressed in units of radioactivity per unit of area for alpha or beta emitters. For SI , this is becquerels per square meter (or Bq/m 2 ). Other units such as picoCuries per 100 cm 2 or disintegrations per minute per square centimeter (1 dpm/cm 2 = 167 Bq/m 2 ) may be used.
The reports say for years Chelyabinsk dumped about 120 million curies of radioactive waste to give you an idea of how much ... The 10 hardest restaurant reservations to book in America. Lighter Side.
[1] [2] It is usually given in units of becquerel per kilogram (Bq/kg), but another commonly used unit of specific activity is the curie per gram (Ci/g). In the context of radioactivity , activity or total activity (symbol A ) is a physical quantity defined as the number of radioactive transformations per second that occur in a particular ...
Radon gas is a radioactive chemical element that is the largest source of background radiation, about 2mSv per year. [17] This is similar to a head CT (see table). Other sources include cosmic radiation, dissolved uranium and thorium in water, and internal radiation (humans have radioactive potassium-40 and carbon-14 inside their bodies from ...
The rep has variously been defined as 83 or 93 ergs per gram of tissue (8.3/9.3 mGy) [13] or per cc of tissue. [ 14 ] In 1953 the ICRU recommended the rad, equal to 100 erg/g as a new unit of absorbed radiation, [ 15 ] but then promoted a switch to the gray in the 1970s.
Spending accelerated sharply in the second quarter to an annual rate of 2.3%, up from 1.5% in the first quarter, as consumers spent a bit less on services but much more on goods.