Question

Calculate the wavelength (in nanometer) associated with a proton moving at $1.0 \times 10^{3} \,ms ^{-1}$. (Mass of proton $=1.67 \times 10^{-27}\, kg$ and $h =6.63 \times 10^{-34}\, Js$ )

• A. 0.40 nm
• B. 2.5 nm
• C. 14.0 nm
• D. 0.32 nm

Answer 1

Answer: (A)

$\lambda =\frac{h}{m v}=\frac{6.63 \times 10^{-34}}{1.67 \times 10^{-27} \times 1 \times 10^{3}} $
$=3.97 \times 10^{-10} $ meter
$=0.397$ nanometer $ \approx 0.40\, nm $