Question

A particle is moving 3 times faster than the speed of an electron. If the ratio of the wavelength of the particle and the electron is $1.8\times {10}^{-4}$, then the particle is:

• A. neutron
• B. $\alpha -particle$
• C. deutron
• D. tritium

Answer 1

The correct option is A neutron

Given:

$\frac{{\lambda }_{particle}}{{\lambda }_{electron}}=1.8\times {10}^{-4}$
$\frac{v_{particle}}{v_{electron}}=3$
According to de-Broglie wavelength,
$\lambda =\frac{h}{mv}$

$\frac{{\lambda }_{particle}}{{\lambda }_{electron}}=\frac{v_{electron}}{v_{particle}}\times \frac{mas{s}_{elctron}}{mas{s}_{particle}}$

$\frac{{\lambda }_{particle}}{{\lambda }_{electron}}=\frac{1}{3}\times \frac{9.1\times {10}^{-31}}{mas{s}_{particle}}$

Mass of the particle = $1.6852\times {10}^{-27}$ Kg which is close to the mass of neutron.