\(neE =\rho\left(\frac{4}{3} \pi r ^{3}\right) \times g\)
\(n \times 1.6 \times 10^{-19} \times 3.55 \times 10^{5}\)
\(=3 \times 10^{3} \times \frac{4}{3} \times \pi \times\left(2 \times 10^{-3}\right)^{3} \times 9.81\)
\(n =173 \times 10^{(3-9-5+19)}\)
\(n =1.73 \times 10^{10}\)