Question

Determine the total charge on 75 kg of electrons

Answer 1

Answer: refer to the explanation given below

Answer 2

Given: mass of electrons- M = 75kg

To Find: Total charge on the electrons - Q =?

Solution:

Formula used:

• Charge on given number of electrons - Q = number of electrons - n × charge of 1 electron - q

Calculating number of electrons in 75kg mass

mass of 1 electron - m = 9.11 × 10⁻³¹kg

number of electrons in 75kg -n = M/m

n = 75/ 9.11 × 10⁻³¹

n = 8.2 × 10³¹ electrons

Calculating charge of  8.2 × 10³¹ electrons

Charge on 1 electron - q = 1.6 × 10⁻¹⁹C

Q = -nq

Q = - 8.2 × 10³¹ × 1.6 × 10⁻¹⁹

Q = 13 × 10¹²C

Q = 1.3 × 10¹³C

Hence, total charge on 75kg of electrons = 1.3 × 10¹³C.