$${\Delta \lambda = \frac{h}{mc} (1 - \cos \phi) \\ = \frac{(6,63 \times 10^{-34}\, \mathrm{J \cdot s})(1 - \cos 85^{\circ})}{(9,11 \times 10^{-31}\, \mathrm{kg})(3,00 \times 10^8\, \mathrm{m/s})} = 2,21 \times 10^{-12}\, \mathrm{m} \approx \underline{\underline{2,2\, \mathrm{pm}}}}$$