Answer
$3.25\times10^{3}ms$
Work Step by Step
λ = $\frac{h}{mv}$ or v= $\frac{h}{mλ}$
h = $6.626\times10^{-34}Js$
m = $1.67\times10^{-27}kg$
λ = 122 pm = $122\times10^{-12}m$ (given)
v = $\frac{6.626\times10^{-34}Js}{1.67\times10^{-27}kg\times122\times10^{-12}m}$ = $3.25\times10^{3}m/s$
