Editing Becquerel (section)

==Definition==
1&nbsp;Bq = 1&nbsp;s<sup>−1</sup>

A special name was introduced for the [[Inverse second|reciprocal second]] (s{{sup|−1}}) to represent radioactivity to avoid potentially dangerous mistakes with prefixes. For example, 1&nbsp;μs{{sup|−1}} would mean 10{{sup|6}} disintegrations per second: {{nowrap|1=({{val|e=−6|u=s}}){{sup|−1}} = {{val|e=6|u=s-1}}}},<ref name="Allisy">{{Citation|last=Allisy|first= A.|title=From the curie to the becquerel|journal=Metrologia|volume=32|issue=6|year=1995|pages=467–479|doi=10.1088/0026-1394/31/6/006|bibcode = 1995Metro..31..467A|s2cid= 250749337}}</ref> whereas 1&nbsp;μBq would mean 1 disintegration per 1 million seconds. Other names considered were [[hertz]] (Hz), a special name already in use for the reciprocal second (for ''periodic'' events of any kind), and fourier (Fr; after [[Joseph Fourier]]).<ref name="Allisy" /> The hertz is now only used for periodic phenomena.<ref name="BIPMtable3">{{cite web|url=http://www.bipm.org/en/publications/si-brochure/section2-2.html#section2-2-2|title=BIPM - Table 3|publisher=[[BIPM]]|quote=(d) The hertz (one per second) is used ''only'' for periodic phenomena, and the becquerel (also one per second) is used ''only'' for stochastic processes in activity referred to a radionuclide.|access-date=2015-07-19}}</ref> While 1&nbsp;Hz replaces the deprecated term [[cycle per second]], 1 Bq refers to one event per second on average for [[aperiodic frequency|aperiodic]] radioactive decays.

The [[gray (unit)|gray]] (Gy) and the becquerel (Bq) were introduced in 1975.<ref name="pmid_1251122">{{Citation|last=Harder|first=D|year=1976|title=[The new radiologic units of measurement gray and becquerel (author's translation from the German original)]|journal=Röntgen-Blätter|volume=29|issue=1 |pages=49–52 |pmid=1251122 |postscript=.}}</ref> Between 1953 and 1975, absorbed dose was often measured with the [[rad (unit)|rad]]. Decay activity was given with the [[Curie (unit)|curie]] before 1946 and often with the [[rutherford (unit)|rutherford]] between 1946<ref name="pmid_17836457">{{Citation|last=Lind|first=SC|year=1946|title=New units for the measurement of radioactivity|journal=Science|volume=103|issue=2687|pages=761–762|pmid=17836457|doi=10.1126/science.103.2687.761-a|postscript=.|bibcode=1946Sci...103..761L |s2cid=5343688 }}</ref> and 1975.