Question

Pennies today are copper-covered zinc, but older pennies are 3.1 g of solid copper. What is the total positive charge in megacoloumbs (106 C) in a solid copper penny that is electrically neutral? The density of copper is 8900 kg/m^3.

Answer 1

Answer:

total positive charge in one copper penny is 0.3 MC

Explanation:

As we know that the atomic number of copper is

z = 29

now moles of copper present in one copper penny is given as

$n = \frac{3.1}{29}$

now total number of copper atoms present in it

$N = moles\times N_a$

$N = \frac{3.1}{29}(6.02\times 10^{23})$

$N = 6.43\times 10^{22}$

Now we know that in one atom there exist 29 protons and 29 electrons

so total positive charge in it

$Q = N(29 e)$

$Q = (6.43\times 10^{22})(29)(1.6 \times10^{-19})$

$Q = 0.3 MC$