What is the mass of #1.7 times 10^23# atoms of zinc?

1 Answer
Jul 30, 2017

Approx. #20*g#........

Explanation:

#6.022xx10^23# individual zinc atoms have a mass of #65.39*g#, and thus to get the mass of #1.7xx10^23*"zinc atoms"# have a mass of......

#(1.7xx10^23*"zinc atoms")/(6.022xx10^23*"zinc atoms"*mol^-1)xx65.39*g*mol^-1=?*g#

From where did I get the number #6.022xx10^23#? Is this in any way special?