Answer :
Final answer:
To give a piece of metal a positive charge of 1 x 10^-6 C, 6.25 x 10^12 electrons must be removed, based on the charge of a single electron (1.602 x 10^-19 C). So the correct answer is option (A).
Explanation:
To determine how many electrons must be removed from a piece of metal to give it a positive charge of 1 x 10-6 C, we can use the relationship that the total charge Q is the product of the number of electrons removed, ne, and the elementary charge, e. The charge of a single electron is approximately -1.602 x 10-19 C. To find the number of electrons that corresponds to a charge of 1 x 10-6 C, we use the equation.
Q = ne * e
Therefore,
ne = Q / e
ne = (1 x 10-6 C) / (1.602 x 10-19 C/electron)
ne = 6.25 x 1012 electrons
So, the correct answer is (a) 6.25 x 1012 electrons.