How many electrons must be removed from a piece of metal to give it a positive charge of $1.0 \times {10}^{–7}C.$

Complete Solution:

Each electron has a charge of approximately e = 1.6 × 10^–19 C.

The total positive charge, Q, on the metal is given as 1.0 × 10^–7 C. Since each electron carries a charge of 1.6 × 10^–19 C, we can find the number of electrons, n, removed by dividing the total charge by the charge of a single electron:

n = Q / e

Substitute the Values:

n = 1.0 × 10^–7 C / 1.6 × 10^–19 C/electron

Calculate n:

n = (1.0 × 10^–7) / (1.6 × 10^–19)

n = 6.25 × 10¹¹ electrons

Final Answer:

To give the piece of metal a positive charge of 1.0 × 10^–7 C, 6.25 × 10¹¹ electrons must be removed.