Question

A copper penny has a mass of 32 g. being electrically neutral, it contains equal amounts of positive and

negative charges. What is the magnitude of these charges in C. A copper atom has a positive nuclear charge

of 3x10^-26 C. Atomic weight of copper is 64g/mole and Avogadro’s number is 6x10^–26 atoms/mole.​

Answer 1

Answer:

number of moles in 32g copper = 32/64 = 0.5 mole.

therefore number of atoms = 0.5 * avogadro number.

i.e. 3* 10^26 atoms.

given that each atom has a positive nuclear charge of 29*1.6*10^-19. because 29 protons in nucleus and each proton charge is 1.6*10^-19C.

Therefore total charge is 3*10^26 * 29*1.6*10^-19

=140*10^7C

=1.4*10^9C