How many atoms of beryllium are equal to 0.39 moles of beryllium?

2.35 x 10²³atoms

Explanation:

Given parameters:

Number of moles of Be  = 0.39moles

Unknown:

Number of atoms  = ?

Solution:

To solve this problem:

                1 mole of a substance contains 6.02 x 10²³ atoms

               0.39 mole of Be will contain 0.39 x 6.02 x 10²³ = 2.35 x 10²³atoms