Question

In 1 gram of solid, there are $5\times {10}^{21}$ atoms. If one electron is removed from every one of $0.1\%$ of atoms of the solid, the charge gained by the solid is

• A. + 0.018C
• B. + 0.8C
• C. +8 $\mu$ C
• D. –0.08C

Answer 1

The correct option is B + 0.8C

Q = ne
$=\frac{0.1}{100}\times 5\times {10}^{21}\times 1.6\times {10}^{-19}$
$=8\times {10}^{-3}\times {10}^{21}\times {10}^{-19}$
= 0.8 C