Answer:
4.5 × 10²³ number of atoms Al
Explanation:
Given data:
Mass of Al = 20 g
Number of atoms of Al = ?
Solution:
The given problem will solve by using Avogadro number.
'It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance" .The number 6.022 × 10²³ is called Avogadro number.
We will calculate the number of moles of Al first:
Number of moles = mass/molar mass
Number of moles = 20 g/ 27 g/mol
Number of moles = 0.74 mol
1 mole = 6.022 × 10²³ number of atoms
0.74 mol × 6.022 × 10²³ number of atoms / 1 mol
4.5 × 10²³ number of atoms Al
