Answer:
Mass = 5.24 g
Step-by-step explanation:
Given data:
Number of atoms of Ca = 7.9×10²² atoms
Mass of Ca = ?
Solution:
First of all we will calculate the number of moles by using Avogadro number.
1 mole contain 6.022×10²³ atoms
7.9×10²² atoms × 1 mol /6.022×10²³ atoms
1.31 ×10⁻¹ mol
0.131 mol
Mass of Ca:
Mass = number of moles × molar mass
Mass = 0.131 mol × 40 g/mol
Mass = 5.24 g