What is the total charge of all the electrons in a 15-kg bar of gold? What is the net charge of the bar? (Gold has 79 electrons per atom and an atomic mass of 197 u.)

answer:

What is the total charge of all the electrons in a 12kg bar of gold? What is the net charge of the bar? (Gold has 79 electrons per atom and an atomic mass of 197u).

I have tried the following but my book gives a different answer.

I know...

1 atomic mass= 1.6605x10^-27kg

gold atomic mass=197u

79 electrons

e charge= 1.6x10^-19C

step 1:    1.6605x10^-27 * 197 = 3.27x10^-25kg weight of a gold atom

step 2:    3.27x10^-25kg / 12kg = 2.725X10^-26 atoms in the bar of gold

step 3:    79e * 2.725x10^26 = 2.15x10^-24 number of electrons in bar of gold

step 4:    2.15x10^-24 * 1.6X10^-19C = 5.978X10^-19

But the answer in the book says the answer should be -4.6X10^8C and the net charge is zero.

Also, I am not understanding why the net charge of the bar is zero.

Can you explain this as well

Explanation: