d
\({\lambda _e} = {\lambda _{{\text{photon }}}} \times {10^{ - 3}}\)

\( \Rightarrow \frac{h}{{mv}} = \frac{c}{v} \times {10^{ - 3}}{\text{s}}\)

\( \Rightarrow v = \frac{{hv}}{{mC \times {{10}^{ - 3}}}}\)

\( = \frac{{6.62 \times {{10}^{ - 34}} \times 6 \times {{10}^{14}}}}{{9.1 \times {{10}^{ - 31}} \times 3 \times {{10}^8} \times {{10}^{ - 3}}}}\)

\( = 1.45 \times {10^6}\)