Final answer:
The half-life of sodium-24 is approximately 24 days.
Step-by-step explanation:
The half-life of a radioactive isotope is the time it takes for half of the sample to decay. In this case, the half-life of sodium-24 is being asked for. We can use the formula for half-life to calculate it:
Half-life = (Time * ln(2)) / (ln(Initial mass / Final mass))
Plugging in the given values, we have:
Half-life = (12 days * ln(2)) / (ln(9.6 g / 1.2 g))
Calculating this expression, the half-life of sodium-24 is approximately 24 days.