Question

Similar to electron diffraction, neutron diffraction microscope is also used for the determination of the structure of molecules. If the wavelength used here is `800 p m`, calculate the characteristic velocity associated with the neutron.

Answer 1

From de Broglie’s equation,
`lambda = (h)/(mv)`
`v = (h)/(mlambda)`
Where,
v = velocity of particle (neutron)
h = Planck’s constant
m = mass of particle (neutron)
`lambda =` wavelength
Substituting the values in the expression of velocity (v),
`v = (6.626 xx 10^(-34) Js)/((1.67493 xx 10^(-27) kg)(800 xx 10^(-12) m))`
`= 4.94 xx 10^(2) ms^(-1)`
`v = 494 ms^(-1)`
`:.` Velocity associated with the neutron `= 494 ms^(-1)`