A sample of pure phosphorus-32 (1532P^{32}_{15}\text{P}1532P) has an initial mass of 4.80 μg4.80\text{ }\mu\text{g}4.80 μg. Phosphorus-32 decays by β−\beta^-β− emission to stable sulfur-32 (1632S^{32}_{16}\text{S}1632S) with a half-life of 14.3 days14.3\text{ days}14.3 days.
What is the mass of sulfur-32 in the sample after 42.9 days42.9\text{ days}42.9 days?
Assume that no material escapes from the sample and the atomic mass difference between phosphorus-32 and sulfur-32 is negligible.
0.60 μg0.60\text{ }\mu\text{g}0.60 μg
1.20 μg1.20\text{ }\mu\text{g}1.20 μg
3.60 μg3.60\text{ }\mu\text{g}3.60 μg
4.20 μg4.20\text{ }\mu\text{g}4.20 μg
