How many atoms are 6.40 grams of sulfur

Number of atoms = 1.20 * 10^23

Explanation:

To calculate the atoms

Let's find the number of mole

n = m/Mm

n = 6.40/32.065

n = 0.1996mole

The number of mole multiples by avogadros number

Avogadros number = 6.02 * 10^23

Number of atom = 0.1996 * 6.02 * 10^23

= 1.20 * 10^23 atoms