A pure Si crystal having \(5\times {10}^{28}\) atoms \({\mathrm{m}}^{-3}\) is dopped with 1 ppm concentration of antimon…

A pure Si crystal having \(5\times {10}^{28}\) atoms \({\mathrm{m}}^{-3}\) is dopped with 1 ppm concentration of antimony. If the concentration of holes in the doped crystal is found to be \(4.5\times {10}^{9}{\mathrm{m}}^{-3}\), the concentration (in \({\mathrm{m}}^{-3}\)) of intrinsic charge carriers in Si crystal is about