Electrostatics

Total atoms in the solid $=6 \times 10^{24}$$0.005 \%$ of atoms lose one electron each.Step 1: Find how many atoms lose an electronNumber of affected atoms $=(0.005 \%) \times (6 \times 10^{24})$$0.005 \% = \; \frac{0.005}{100} = 5 \times 10^{-5}$⇒ Number of atoms losing electrons $=6 \times 10^{24} \times 5 \times 10^{-5}=3 \times 10^{20}$Step 2: Each atom loses one electronEach lost electron corresponds to a positive charge gained by the solid equal to the charge of that electron $(e=1.6 \times 10^{-19} \mathrm{C})$.Step 3: Total charge gained$\;Q= (3 \times 10^{20}) \times (1.6 \times 10^{-19})$$\;Q=4.8 \times 10^1=48 \mathrm{c}$