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Radioactive Decay: Specific Activity A
specific
M
N
T
2ln
M
N
A
A
2/1
A
specific
= λ=
•
Molar mass of
226
Ra is 226.02 g/mol
•
T
1/2
of decay for
226
Ra is 1600 a
•
Thus considering 1a = 365x24x60x60 s T
1/2
= 5.0458 x 10
10
s
•
and N
A
= 6.02214 x10
23
mol
-1
(Avogadro-Number)
•
A
spec
for
226
Ra is 3.7x10
10
Bq/g = 37 GBq/g =1 Ci/g