Question

Calculate the wavelength in ‘nm’ associated with a proton moving at $1\times {10}^{3}mse{c}^{-1}$ ( mass of proton $=1.67\times {10}^{-27}kg,h=6.63\times {10}^{-34}Jsec$)

• A. 0.032 nm
• B. 0.40 nm
• C. 2.5 nm
• D. 14 nm

Answer 1

The correct option is B 0.40 nm

$\lambda =\frac{h}{mv}=\frac{6.63\times {10}^{-34}}{1.67\times {10}^{-27}\times {10}^8}=0.397\times {10}^{-9}m\approx 0.4nm$