Not quite. That would only be true if it had a half-life of like 5 seconds. In that case it would break down so fast it would pretty much disinegrate before your eyes. Einsteinium-253 has a half-life of about 20 days. Einsteinium-252 has a half-life of of about 470 days. So depending on which isotope is used, and how long it takes to contain it, it would be possible to get the exact mass in a container at any given time.

Now, Chruser, since I still don't understand what a vendekometer and a xennoliter are, I can't attempt to answer. but I'll go find out right now....

I DONT WANT A SIG!!!!
Your REALLY gonna want to click this