Short Answer

The experiment that supports the wave nature of particles is the Davisson–Germer experiment. In this experiment, a beam of electrons was directed at a nickel crystal, and the scattered electrons produced an interference pattern similar to waves. This confirmed that electrons behave like waves.

This experiment provided the first direct experimental proof of de Broglie’s hypothesis, which states that moving particles have a wavelength associated with them. The Davisson–Germer experiment became one of the strongest foundations of quantum mechanics.

Detailed Explanation :

Experiment supporting wave nature of particles

The wave nature of particles is one of the most important ideas in modern physics. It was first proposed by Louis de Broglie in 1924, who suggested that not only light but even matter such as electrons, protons, and atoms behave like waves. This idea was surprising because matter was always considered to be made only of particles. To prove this theory, a strong experimental demonstration was needed. The experiment that provided this proof was the Davisson–Germer experiment.

The Davisson–Germer experiment, performed in 1927, showed that electrons can produce a diffraction pattern, which is a property of waves. Diffraction and interference are wave-like behaviours that cannot be explained by particle theory alone. When electrons were allowed to strike a nickel crystal, they scattered in specific directions and produced bright and dark spots, similar to the pattern produced by X-rays. Since X-rays are electromagnetic waves, seeing the same pattern from electrons proved that electrons also behave like waves.

This experiment confirmed de Broglie’s hypothesis and became a major turning point in quantum physics. It showed that the wave-particle duality applied not only to light but also to matter. The success of this experiment strengthened the development of quantum mechanics and changed the way scientists understood the microscopic world.

Davisson–Germer experiment and its significance

In the Davisson–Germer experiment, electrons were emitted from a heated filament and accelerated using an electric potential. These fast-moving electrons formed a narrow beam. The beam was then directed at a nickel crystal target. When the electrons struck the crystal, they scattered in various directions.

A detector measured the intensity of the scattered electrons at different angles. Surprisingly, the intensity was not uniform. At certain angles, the intensity was very high, showing bright peaks. At other angles, the intensity was much lower, creating dark regions. This pattern matched the interference pattern produced by waves undergoing diffraction.

This experiment was similar to how X-rays scatter when they hit a crystal structure. In both cases, waves interfere constructively and destructively, forming a diffraction pattern. Since electrons produced the same type of pattern, it proved that electrons have wave properties.

The wavelength calculated from the pattern matched the de Broglie wavelength formula:

λ = h/p

where
λ is the wavelength,
h is Planck’s constant,
p is the momentum of the electron.

The agreement between the observed wavelength and the calculated de Broglie wavelength was crucial proof that the wave formula for particles was correct.

Why this experiment was important

The Davisson–Germer experiment was important for several reasons:

1. First direct evidence for matter waves
   Before this experiment, de Broglie’s theory was only an idea. The experiment provided real proof that matter behaves like waves.
2. Showed that electrons produce diffraction patterns
   Diffraction is a wave phenomenon. Only waves can bend around obstacles and interfere to form bright and dark fringes.
3. Confirmed the de Broglie relation λ = h/p
   The wavelength obtained from the experiment perfectly matched the calculated value, proving the accuracy of de Broglie’s hypothesis.
4. Supported the foundation of quantum mechanics
   The experiment encouraged scientists to treat particles as wave packets and helped Schrödinger develop his wave equation.
5. Marked a shift from classical to quantum physics
   Classical physics could not explain the experimental results. Only the wave theory of matter could describe the pattern.

Applications based on wave nature of particles

The confirmation of matter waves has led to many modern technologies and scientific tools such as:

Electron microscopes:
Electron waves have very small wavelengths, allowing microscopes to see extremely small structures like viruses, atoms, and molecules.

Diffraction studies:
Electron diffraction is used to study crystal structures and molecular arrangements.

Quantum mechanics:
Wave nature forms the basis of Schrödinger’s wave equation, which describes the motion of electrons in atoms.

Semiconductor devices:
The behaviour of electrons in solids, essential for transistors and integrated circuits, relies on their wave properties.

Nanotechnology and quantum computing:

The wave nature of particles helps explain tunneling and other quantum behaviours used in modern technologies.

Thus, the experiment not only proved de Broglie’s idea but also opened the door to many scientific advancements.

Conclusion

The Davisson–Germer experiment is the key experiment that supports the wave nature of particles. It showed that electrons produce diffraction patterns just like waves, proving de Broglie’s hypothesis. This experiment helped establish quantum mechanics, showed that all particles have wave properties, and laid the foundation for many modern technologies such as electron microscopes and semiconductor devices.