# Half-Life, Nuclear Decay Related Problem (answer in units of Ci)

1. May 12, 2009

### Spartan Erik

1. The problem statement, all variables and given/known data

The half-life of an isotope of phosphorus is 14 days. If sample contains 2.9 × 10^16 decays such
nuclei, determine its activity. Answer in units of Ci.

2. Relevant equations / 3. The attempt at a solution

I know that one Ci is equal to 3.7*10^10 bq (or decay per second), I'm just not sure how I can relate this to the half-life of phosphorus.

==EDIT==

Nevermind guys, I got the formula after some searching. Ultimately, (decays*ln2)/(half life*24*3600*3.7e10)

Last edited: May 12, 2009