Question

(10 POINTS)

Use the periodic table to determine how many atoms of phosphorus (P) are in a sample that has a mass of 172.90 g.

A. 3.48 × 1021 atoms

B. 1.97 × 1022 atoms

C. 3.36 × 1024 atoms

D. 1.04 × 1026 atoms

Answer 1

Hello there.

Use the periodic table to determine how many atoms of phosphorus (P) are in a sample that has a mass of 172.90 g.

C. 3.36 × 1024 atoms

Answer 2

Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles. We do as follows:

172.90 g ( 1 mol / 30.97 g ) (6.022 x 10^23 atoms / mol) = 3.36 × 10^24 atoms

Therefore, option C is the answer.