At temperature T , the average kinetic energy of any particles is `(3)/(2)` kT. The de Broglie wavelength follows the order :

Options

A. Visible photon `to` Thermal neutron `gt` Thermal electron
B. Thermal proton `gt` Thermal electron `gt` Visible photon
C. Thermal proton `gt` Visible photon `gt` Thermal electron
D. Visible photon `to` Thermal electron `to` Thermal neutron

Answer

B

Explanation

Kinetic energy of any particle ` = (3)/(2) KT`
Also K.E. `= (1)/(2) mv^(2)`
`(1)/(2)mv^(2) = (3)/(2) KT rArr v^(2) = (3KT)/(m)`
`v = sqrt((3KT)/(m))`
De - broglie wavelenght `= lambda = (h)/(mv) = (h)/(m sqrt((3KT)/(m)))`
`lambda = (h)/(sqrt(3KTm)) lambda prop (1)/(m)`
Mass of electron `lt` mass of neutron `lambda`(electron) `gt lambda ` (neutron).