How many atoms are in a sample containing 7 moles of phosphorus?

1. d.4.125 x 10²⁴ atoms

2. c. 487.73 g

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

1. 7 moles of phosphorus, so n=7, then number of atoms :

2. 2.5 moles of Pt, so n=2.5, the mass of Pt(MW=195,084 g/mol) :

increased stability in the completion of fluorine's outer shell.