Hi all,

This is my first time here, please help me along

Qn: Calculate the De Broglie wavelength of a neutron with atranslational kinetic energy = kTat 300K.

k = boltzmann constant = 1.38 x 10^-23 JK-1

Solution:

λ = h / p

= h / (2mE)^1/2 (E: kinetic energy)

= h / (2mkT)^1/2 (substitute E with kT, the translational kinetic energy)

why do we use translational energy = kT here?

I googled, most of the webpage suggest KE = 3/2 kT (or kBT) (kB: boltzmann constant)

I am trying to understand why the question omit 3/2?

To my understanding 3/2 is to account for the 3 axis of direction, am i right? there is x, y, and z direction.

So instead of KE = 1/2 kT, we get 3/2 kT.

Any guidance is appreciated