Answer:
3.79 ×10²³ atoms
Step-by-step explanation:
Given data:
Mass of Se = 49.6 g
Number of atoms = ?
Solution:
Formula:
Number of moles = mass/ molar mass
Molar mass of selenium is 78.96 g/mol.
by putting values,
Number of moles = 49.6 g/ 78.96 g/mol.
Number of moles = 0.63 mol
Number of atoms:
Now we will apply Avogadro number.
1 mole contain 6.022×10²³ atoms
0.63 mol × 6.022×10²³ atoms / 1 mol
3.79 ×10²³ atoms