Verified answer

Convert 76 g of iron to moles by dividing the 76 g by the atomic mass 55.847 g*mol^-1 to get moles then multiply that Avogadro's number 6.022x10^23. = 8.195e+23

There might be a quicker way but this is how I would do it...

First you have to convert it to moles.

For this you need to know the gram molecular weight of iron.

I looked it up and got 55.845 grams/mol.

So you have to divide it...

76 / 55.845 = approx. 1.361 moles.

Now to get the number of atoms for that many moles, you have to multiply by Avogadro's number (6.02 x 10^23)

1.361 * 6.02 * 10^23

The answer is 8.19 x 10^23 atoms.

Hope that helps.