What molar quantity is represented by #3.011xx10^23*"magnesium atoms"#?

2 Answers
Dec 29, 2017

Answer:

If I have a half a dozen magnesium atoms, how many atoms would that be?

Explanation:

And this question is PRECISELY the same as the one you asked EXCEPT that we use #"the dozen"# as our metric instead of the #"Avocado number"#, i.e. #N_A=6.022xx10^23*mol^-1#

And so we take the product...

#6.022xx10^23*mol^-1xx0.5*mol-=3.011xx10^23*"magnesium atoms"#. You know the mass of this quantity....

Dec 29, 2017

Answer:

#3.01 xx10^23# #"atoms"#.

Explanation:

#6.02xx10^23# (Avogadro's constant) indicates the number of atoms in a mole of any element, so basically:

#"1 mole of Mg " -> " " 6.02 xx10^23# #"atoms"#
#"0.5 moles of Mg " -> " " "? atoms"#

So

#"0.5 moles" xx ( 6.02xx10^23 "atoms")/"1 mole"#

which equals to half of Avogadro's constant.