# Question #b56d8

##### 1 Answer
Jun 16, 2014

APPLY MOLE CONCEPT -
" In a molecule or an atom 1 mole is equivalent to its atomic weight & 1 mole contains 6.022 x 10^23 atoms / molecules ( Avagrado number) "

Here ,

Fe = 56 g (atomic wt. of 1 element of Fe) = 1 mole (as it is relative to C-12) = 6.022 x 10^23 atoms of Fe

Now applying basic maths , we have ;
6.022 x 10 ^23 atoms of Fe has ---- 56 g of mass
150 x 10^12 atoms of Fe will have ----56 x 150 x 10^12 / 6.022 x 10 ^23
= 1.39 x 10 ^-8 $A n s w e r$