1. Find the molar mass of sulfur:

* The molar mass of sulfur (S) is 32.06 g/mol. This means that one mole of sulfur atoms weighs 32.06 grams.

2. Convert grams of sulfur to moles:

* Divide the given mass of sulfur (78.4 g) by the molar mass of sulfur:

78.4 g / 32.06 g/mol = 2.44 mol

3. Calculate the number of sulfur atoms:

* Use Avogadro's number (6.022 x 10^23 atoms/mol) to convert moles of sulfur to atoms:

2.44 mol * 6.022 x 10^23 atoms/mol = 1.47 x 10^24 atoms

Therefore, there are approximately 1.47 x 10^24 sulfur atoms in 78.4 grams of sulfur.