Question

A person shuffles across the rug and then place his finger near his friend's nose, causing a small spark that transfers about 10^−9C of charge from the person to his friend. Determine the number of electrons transferred. e=1.6×10^−19C.

Express your answer using two significant figures.

Answer 1

`n = (10^(-9)C)/(1.6 x10^(-19)C)= 6.25 x10^(9) electrons \approx 6.3 x10^(9) electrons`

Step-by-step explanation:

For this case we know that the charge associated to the transferred electrons of the small spark is
`10^(-19)C` and we want to find the number of electrons transferred.

From the properties of matter we know that the charge of the electron is

`q_e = |-1.6 x10^(-19)C |= 1.6 x10^(-19)C`

And we know that the total charge is given by this expression:

`Q = n e`

Where Q represent the charge, n the number of electrons and e the charge of the electron.

If we solve for n we got:

`n = (Q)/(e)`

And replacing we got:

`n = (10^(-9)C)/(1.6 x10^(-19)C)= 6.25 x10^(9) electrons \approx 6.3 x10^(9) electrons`