A nuclear physics laboratory requires a sample containing 1.0×108 undecayed atoms of polonium-210 exactly at 09:00 h on Monday for a counting experiment. The half-life of polonium-210 is 138d. The only practical opportunity to prepare the sample is at 09:00 h on the preceding Friday.
(i) Calculate the decay constant of polonium-210.
(ii) Determine the number of atoms that must be prepared on Friday so that the required number is still present on Monday.
(iii) Given the molar mass of polonium-210 is 210gmol−1 and Avogadro’s number NA=6.02×1023mol−1, calculate the mass of polonium-210 corresponding to the number of atoms obtained in part (ii).