Question

If the velocity of an electron in Bohr’s first orbit is $2.19 \times 10^6\, m\, s^{-1}$, what will be the de Broglie wavelength associated with it?

• A. $2.19 \times 10^{-6}\,m$
• B. $4.38 \times 10^{-6}\,m$
• C. $3.32 \times 10^{-10}\,m$
• D. $3.32 \times 10^{10}\,m$

Answer 1

Answer: (C)

$\lambda=\frac{h}{mv}$
$=\frac{6.626 \times 10^{-34}\,J\,s}{9.11 \times 10^{-31}\,kg \times 2.19 \times 10^{6}\,m\,s^{-1}}$
$=3.32\times10^{-10}\,m$