As per de-broglie formula a microscopic particle of mass 100 g and moving at a velocity of 100 cm/sec will have a wavelength of:

According to De-Broglie equation;
Wavelength $\left(\mathrm{\lambda }\right)=\frac{\mathrm{h}}{\mathrm{mv}}$
Given: $\mathrm{m}=100\mathrm{g},\mathrm{v}=100\mathrm{cm}/\sec$
$\mathrm{h}=6.6\times {10}^{-34}\mathrm{Js}=6.6\times {10}^{-27}\mathrm{erg}-\mathrm{s}$
on substituting values, we get
$\lambda =\frac{6.6\times {10}^{-27}}{100\times 100}=\frac{6.6\times {10}^{-27}}{{10}^4.}=6.6\times {10}^{-31}\mathrm{cm}/\mathrm{s}$