Question

The speed of a photon is one hundredth of the speed of light in vacuum. What is the de Broglie wavelength? Assume that one mole of protons has a mass equal to one gram, $h=6.626\times 10^{-27}$ erg sec

• A. $3.31\times 10^{-3}\mathring{A}$
• B. $1.33\times 10^{-3}\mathring{A}$
• C. $3.13\times 10^{-2}\mathring{A}$
• D. $1.31\times 10^{-2}\mathring{A}$

Answer 1

Answer: (B)

$m=\frac{1}{6.023\times 10^{23}}g$
$\lambda =\frac{h}{mv}$
$=\frac{6.626\times 10^{-27}}{1\times 3\times 10^{8}cmse{c}^{-1}}\times 6.023\times 10^{23}$
$=1.33\times 10^{-11}cm$