Answer:
3.36 × 10^24 atoms
Step-by-step explanation:
We are given;
- Mass of phosphorus is 172.90 g
We are supposed to calculate the number of atoms of phosphorus;
- Note that 1 mole of an element contains 6.022 × 10^23 atoms
In this case;
- 1 mole of phosphorus contains 6.022 × 10^23 atoms
- But; Molar mass of phosphorus is 30.97 g/mol
Therefore;
30.97 g contain 6.022 × 10^23 atoms
Thus, for 172.90 g
= (172.90 g /30.97 g) × 6.022 × 10^23 atoms/mol
= 3.36 × 10^24 atoms
Thus, 172.90 g of phosphorus contains 3.36 × 10^24 atoms