Crystal diffraction experiments can be performed using X-rays, or electrons accelerated through appropriate voltage. Which probe has greater energy? An X-ray photon or the electron? (For quantitative comparison, take the wavelength of the probe equal to `1Å`, which is of the order of interatomic spacing in the lattice), `m_(e)=9.11xx10^(-31)kg`.

Explanation

Given , wavelength , `lamda=1 Å=10^(-10)m`
If `E_k` is the kinetic energy of electron , then
`lamda=h/(sqrt(2m_eE_k))`
`implies1xx10^(-10)=(6.625xx10^(-34))/(sqrt(2xx9.1xx10^(-33)xxE_k))`
`E_k=150eV`
This gives the energy of electron.
Also , energy of photon,
`E=(hc)/lamda`
`=(6.625xx10^(-34)xx3xx10^8)/((1xx10^(-10)xx1.6xx10^(-19)))`
`= 12.4 xx10^3eV`
`=12.4 keV.`