This is the English version of turbocalc sheet "atomactivity"
You enter the name of the isotope, its halfing-time T½,
and the unit in their proper columns, so you get
the decaying constant and it`s unit in their columns.
The activity of a piece of matter is got, when the amount of
the piece in moles is multiplied with the decaying constant
in Becquerels. Result is in Becquerelmoles. One becquerel
is one decay per second, or 1/s.

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
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[generic]                18117  195765   9.3% -lh5- b969 Oct 28  2000 atomactivity2.TCD
[generic]                  336     615  54.6% -lh5- 346c Oct 28  2000 atomactivity2.readme
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total         2 files   18453  196380   9.4%            Jul 28  2002