Phosphorus-32 2 is a commonly used radioactive nuclide in biochemical research, particularly in studies of nucleic acids. The half-life of phosphorus-32 is 14.3 days. What mass of phosphorus- 32 is left from an original sample of 175 $\mathrm{mg}$ $\mathrm{Na}_{3}^{32} \mathrm{PO}_{4}$ after 35.0 days? Assume the atomic mass of $^{32} \mathrm{P}$ is 32.0 $\mathrm{u} .$