Question

How many electrons are necessary to produce a charge of -0.80 C

Answer 1

Answer:

The charge carried by 1 electron : 1.602 * 10^(-19) C

so, 1C = 1e/1.6×10^(-19) = 6.24 * 10^18

now, (-0.80)C = - 4.99 * 10^18 electrons are necessary

Answer 2

we have to find the number of electrons needs to produce a charge of -0.8 C.

solution : charge on each electron is -1.6 × 10⁻¹⁹ C.

it is the smallest charge. you should understand that charge is quantized. it means, the total charge is just the integral multiple of the charge of an electron.

i.e., Q = ne⁻

where Q is total charge , n is number of electrons and e⁻ is the charge on each electron.

here, Q = -0.8C , e⁻ = -1.6 × 10⁻¹⁹ C

⇒ -0.8 = n × 1.6 × 10⁻¹⁹ C

⇒ n = 0.8/1.6 × 10¹⁹ = 5 ×  10¹⁸

therefore the number of electrons needs to produce a charge of -0.8C is 5 × 10¹⁸ .