Can you explain how to do this?

Question

Can you please explain how to do this.

Calculate the mass of 500. atoms of iron.

Answer 1

Molar mass of Fe=55.85

According avogadro this is the mass of 6.022*10^23 atoms

so 1 atom weighs

55.85/6.022*1^23

and 500 atoms

55.85*500/6.022*10^23=4.637*10^-20g

Answer 2

In order to do this, you need the atomic mass of Iron, 55.85 g/mol, and Avogadro's number, 6.022 x 10^23 anything/mol.

Avogadros number tells us how much of something is in a mole--It could be anything.  For example, we could have a mole of boogers, it would simply be 6.022 x 10^23 boogers in one mole of boogers.  So lets begin:

500 Iron Atoms * 1 mol/6.022 x 10^23 Iron Atoms = 8.3 x 10^-22 mol Iron atoms

Now that we have moles of Iron, we need to convert to mass using the atomic mass of iron.  The atomic mass tells us how much something weighs per mole of that something:

8.3 x 10^-22 mol Iron atoms * 55.85 g/mol = 4.6 x 10^-20 g of Iron  

Not a lot of Iron!

Answer 3

1 mole of iron weighs 55.85g

there are 6.022x10*23 atoms (10 to the power of 23) Avogadro's constant in a mole of iron

so 6.022x10*23 = 55.85g

       500           = ?

(500 x 55.85)/6.022x10*23 = 4.64x10-20g

there you go there now