How many moles do #8.1xx10^18# calcium atoms represent?

1 Answer
Jan 30, 2016

Answer:

Approx. #1/100000"th"# of a mole.

Explanation:

In #1# #mol# of particles there are #6.022# #xx# #10^23# individual particles. So we just divide the quoted number by this, Avogadro's number, to get an answer in mol.

#(8.1xx10^18" calcium atoms")/(6.022xx10^23 " calcium atoms"*mol^-1)# #=# #??# #mol#

What is the mass of this number of calcium atoms?