How many moles of atoms are in each elemental sample? (Remember to use the correct number of significant figures in your answer. The first problem will have 2 sig figs and the rest will have 3 sig figs) a. 4.6 x 1024 Pb atoms= mol Pb b. 2.87 x 1022 He atoms= mol He c. 7.91 x 1023 K atoms= mol K d. 4.41 x 1021 Ca atoms= mol Ca