1. Understand the Chemical Formula

* Ammonium sulfide has the chemical formula (NH₄)₂S. This means each molecule contains:

* 2 nitrogen atoms (N)

* 8 hydrogen atoms (H)

* 1 sulfur atom (S)

2. Calculate the Number of Molecules

* Avogadro's number tells us that there are 6.022 x 10²³ molecules in one mole of any substance.

* Therefore, in 7.40 mol of ammonium sulfide, there are:

(7.40 mol) * (6.022 x 10²³ molecules/mol) = 4.45 x 10²⁴ molecules

3. Calculate the Total Number of Hydrogen Atoms

* Since each molecule has 8 hydrogen atoms, the total number of hydrogen atoms is:

(4.45 x 10²⁴ molecules) * (8 H atoms/molecule) = 3.56 x 10²⁵ hydrogen atoms

Answer: There are approximately 3.56 x 10²⁵ hydrogen atoms in 7.40 mol of ammonium sulfide.