Question

How many atoms are found in a 15.5 g sample of bismuth?

Answer 1

4.47 x 10²² atoms

Step-by-step explanation:

Given parameters:

Mass of Bismuth = 15.5g

Unknown:

Number of atoms = ?

Solution:

To find the number atoms, first solve for the number of moles in this element first.

Number of moles =
`(mass)/(molar mass)`

Number of moles =
`(15.5)/(209)` = 0.074mole

So:

1 mole of a substance contains 6.02 x 10²³ atoms

0.074 mole of Bismuth will contain 0.074 x 6.02 x 10²³ atoms

= 4.47 x 10²² atoms