Final answer:
To calculate the number of iodine atoms in 508 amu, 19,463 amu, and 7.28 x 10²⁴ amu samples, we divide each mass by the atomic mass of iodine and then multiply by Avogadro's number. This gives approximately 2.41 x 10²⁴ atoms, 9.23 x 10²⁵ atoms, and 3.46 x 10²⁶ atoms, respectively.
Step-by-step explanation:
To determine how many atoms are in a given sample of naturally occurring iodine, we first need to know the average atomic mass of naturally occurring iodine, which is approximately 126.90 amu. Because samples in atomic mass units (amu) refer to the mass of individual atoms, and one mole of any substance contains Avogadro's number of atoms, which is approximately 6.02 × 1023 atoms/mol, we can use this information to find the number of atoms in each sample:
- (a) For 508 amu of iodine: 508 amu / 126.90 amu/mol = 4.00 moles. Therefore, 4.00 moles × 6.02 × 1023 atoms/mol = approximately 2.41 × 1024 atoms.
- (b) For 19,463 amu of iodine: 19,463 amu / 126.90 amu/mol = 153.35 moles. Therefore, 153.35 moles × 6.02 × 1023 atoms/mol = approximately 9.23 × 1025 atoms.
- (c) For 7.28 × 1024 amu of iodine: 7.28 × 1024 amu / 126.90 amu/mol = 57.40 moles. Therefore, 57.40 moles × 6.02 × 1023 atoms/mol = approximately 3.46 × 1026 atoms.