Question

A radioactive sample contains 2.94 μg of pure11C, which has a half-life of 20.4 min. a)...

A radioactive sample contains 2.94 μg of pure11C, which has a half-life of 20.4 min.

a) How many moles of 11C is present ini- tially? The value of Avogadro’s number is

6.02 × 1023 nuclei/mol. Answer in units of mol.

b) Find the number of nuclei present initially. Answer in units of nuclei.

c)Find the initial activity of the sample. Answer in units of Bq.

d)Find the activity of the sample after 6.97 h. Answer in units of Bq.

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