Since, charge of electron = 1.6 × 10^–19 C

No. of electrons = n

According to the question,

n × 1.6 × 10^–19 = 1 C

n = 1/1.6 x 10^-19 C

n = 10⁹/1.6 x 100/16 x 10¹⁸

n = 6.25 × 10¹⁸

1 C = 6.25 × 10¹⁸ electrons