How many atoms of zinc are found in 2.50 mols of zinc?

Hey there!

There are 6.022 x 10²³ atoms in one mole.

We have 2.50 moles.

2.50 x 6.022 x 10²³ = 1.51 x 10²⁴

There are 1.51 x 10²⁴ atoms of zinc in 2.50 mols of zinc.

Hope this helps!

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

a is the correct answer