One uranium atom has a mass of #3.95 x 10^-22# grams. How would you work out an estimate for the number of uranium atoms in 1 kg of uranium?

1 Answer
Dec 12, 2016

Well, divide #"one kilogram"# by the mass of one uranium atom......

Explanation:

And thus, #(1000*g)/(3.95xx10^-22*g*"atom"^-1)#

#=# #"A large number of uranium atoms."#

This is a molar quantity of #(1000*g)/(238.1*g*mol^-1)~=4*mol#.

And so there are approx. #4xxN_A# #"uranium atoms"#, where #N_A="Avogadro's number, "6.022xx10^23#.