posted by Lindsey .
A helium atom weighs 6.65 X 10 to the negative 24 grams. How many helium atoms are contained in a 1.0 g sample?
to get the number of He atoms, we dive the given mass to the mass of each He:
1.0 / (6.65 x 10^(-24)) = 1.50376 x 10^23 He atoms
hope this helps~ :)