Respuesta :

Answer:

4.03 × 10²² particles of beryllium sulfide.

Explanation:

The formula to find the number of particles is:

Number of particles/atoms = number of moles × (6.02 × 10²³)

6.02 × 10²³ = Avogadro's number

But first, we will have to find the number of moles. This can be found using the formula:

Number of moles = mass ÷ Mr

  Mr of BeS = 9 + 32.1 = 41.1

  Number of moles = 2.74 ÷ 41.1 = 0.067 mol

Now that we know the number of moles, we can find the number of particles.

   Number of particles = 0.067 × 6.02 × 10²³

∴ Number of particles =  4.03 × 10²²