Final answer:
To determine the number of argon atoms in 1.5 × 102 g of argon, calculate the moles using the molar mass, and then multiply by Avogadro's number, yielding approximately 2.26 × 1025 argon atoms.
Step-by-step explanation:
To find out how many argon (Ar) atoms are present in 1.5 × 102 g of argon, we need to use the molar mass of argon and Avogadro's number. The molar mass of argon is approximately 39.948 g/mol, according to the periodic table.
First, we calculate the number of moles of argon in the given mass:
- Number of moles = mass (g) / molar mass (g/mol)
- Number of moles = 1.5 × 102 g / 39.948 g/mol
- Number of moles = 3.755 moles (approximately)
Next, we use Avogadro's number to find the number of atoms:
- Number of atoms = number of moles × Avogadro's number
- Number of atoms = 3.755 moles × 6.022 × 1023 atoms/mol
- Number of atoms = 2.26 × 1025 atoms (approximately)
Therefore, there are approximately 2.26 × 1025 argon atoms in 1.5 × 102 g of argon.