How many moles are contained in 7.88 x 1024 atoms of Iron?

Two things that biomedical has invented or innovated

At room temperature what happens to the average kinetic energy of the molecules of a solid, liquid, and a gas

Tin has ten stable isotopes. the heaviest, 124sn, makes up 5.80% of naturally occuring tin atoms. how many atoms of 124sn are present in 82.0 g of naturally occurring tin? what is the total mass of the 124sn atoms in this sample?