Question

Hore many electrons must be removed from a piece of metal
so as to leave it with a positive charge of 3.2*10^-17 coulomb​

Answer 1

Heya,

we know,

charge on an electron =

$1.6 \times {10}^{ - 19}$

Since, it has charge of

$3.2 \times {10}^{( - 17)}$

An electron of thus much charge must have been removed.

Hence, no. of electron removed =

$\frac{total \: charge}{chr \: on \: on e \: elec}$

$\frac{3.2 \times {10}^{ - 17} }{1.6 \times {10}^{ - 19} } \\ = >200$

Hence, the answer is 200.

Regards

Kshitij