Given below are two statements :
Statement I : Davisson-Germer experiment establishes the wave nature of electrons.
Statement II : If electrons have wave nature, they can interfere and show diffraction.
In the light of the above statements choose the correct answer from the option given below :

Solution

Physics sir · 5 steps

Davisson and Germer saw electrons diffract off a crystal, and only waves diffract. Both statements hold.

1. The experiment. A beam of electrons accelerated through 54 V was fired at a nickel crystal. The scattered intensity showed a sharp peak at 50°, a diffraction maximum from the regularly spaced rows of atoms.
2. Check the wavelength. The de Broglie wavelength predicted for these electrons matches the wavelength measured from the diffraction peak.

   λ = 12.27/√V Å = 12.27/√54 Å ≈ 1.67 Å

3. Statement I. This match is the experimental proof that electrons behave as waves. So Statement I is true.
4. Statement II. Interference and diffraction are what waves do when they overlap or meet an obstacle about as small as their wavelength. A wave-like electron must show them too, which is exactly what the crystal revealed. So Statement II is true.
5. So. Both statements are true, which is option (a).

The idea to keep. Diffraction and interference are the fingerprint of a wave. Whenever particles produce a diffraction pattern, as electrons did off nickel, that is proof of their wave nature.

Answer from the NTA final answer key. Solution by PrepWiser.