What is the mass, in grams, of 122 atoms of aluminum? Round your answer to proper significant figures.

Mass = 547.02 × 10⁻²³g

Explanation:

Given data:

Number of atoms of Al = 122 atom

Mass in gram = ?

Solution:

Avogadro number:

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.

1 mole = 6.022 × 10²³ atoms

122 atom/6.022 × 10²³ atoms ×  1 mol

20.26× 10⁻²³ mol

Mass in gram:

Mass = number of moles  × molar mass

Mass = 20.26× 10⁻²³ mol  × 27 g/mol

Mass = 547.02 × 10⁻²³g

the awnser is group 12