According
to the Avogadro's Constant, 1 mole of substance has 6.02214086 × 10²³
(Unit is mol⁻¹) particles.
This means, 1
mole = 6.02214086 × 10²³ molecules / atoms
Given K atoms =
1.72 x 10²³
Moles of K = 1.72 x
10²³ / 6.02214086 × 10²³ mol⁻¹
= 0.286 mol
Moles (mol) = mass (g) / molar mass (g/mol)
Molar mass of K = 39.1 g/mol
Mass of K = 0.286 mol x 39.1 g/mol
= 11.18 g
Hence, 1.72 x
10²³ of K atoms have 11.18 g of mass.
