A copper coin has mass `3.1 xx 10^(-3)` kg . What is the magnitude of charge on copper coin , if the copper atom has a positive nuclear charge of `4.6 xx 10^(-18)` C and 1 mole of copper = 64 g ?

Explanation

Given ,
`64 xx 10^(-3)` kg contains `6.02 xx 10^(23)` atoms
`therefore 3.1 xx 10^(-3)` kg contains
`= (6.02 xx 10^(23) xx 3.1 xx 10^(-3))/(64 xx 10^(-3))` atoms
`= 2.92 xx 10^(22)` atoms
1 copper atom has a positive nuclear charge `= 4.6 xx 10^(-18)` C
`therefore 2.92 xx 10^(22)` copper atoms have nuclear charge = `(4.6 xx 10^(-18)) xx (2.92 xx 10^(22))`
`= 13.43 xx 10^(4) C = 1.34 xx 10^(5) C`