A 952 × 10^-5 Mol Sample of Rubidium-86 Emits 8

Multiple Choice

A 9.52 × 10^-5 mol sample of rubidium-86 emits 8.87 × 10¹⁶  particles in one hour. What is the half-life of rubidium-86?

A) 2.23 × 10^-3 h
B) 1.55 × 10^-3 h
C) 448 h
D) 645 h
E) none of the above