Question

using average atomic masses for each of the following elements calculate the mass in any of 5x10"25 sodium atoms

Answer 1

number of Na atoms = 5 x 10^25

moles of Na atoms = number of atoms / avagadro number

                              = 5 x 10^25 / 6.023 x 10^23

                             = 83.0

Na molar mass = 23 .0 g / mol

mass of Na = moles x molar mass

                  = 83.0 x 23.0

                  =1909 g

mass of Na atoms = 1909 g