All matter has wave character with wavelength equal to Planck's constant divided by momentum.
Practise Atomic Structure & Periodicity All Atomic Structure & Periodicity topics
In 1924 Louis de Broglie proposed that every moving particle has an associated wave with wavelength lambda = h / (m v), where m is the mass and v the speed. The wave character is negligible for everyday objects, whose wavelengths are far too small to observe, but it is significant for electrons and other light particles. It explains why only certain Bohr orbits are allowed: the electron wave must fit a whole number of wavelengths around the orbit. Davisson and Germer's electron diffraction experiments in 1927 confirmed the hypothesis. The idea was a key step toward wave mechanics.
Key ideas: Every moving particle has wavelength lambda = h / (m v) = h / p. An electron at 10^6 m per s has lambda of 0.73 nm, comparable to atomic sizes, while a 0.15 kg ball at 40 m per s has 1.1 x 10^-34 m, undetectable. A stable Bohr orbit fits a whole number of wavelengths: 2 pi r = n lambda.
Common mistakes and connections: Students use mass in grams instead of kg in h / mv, giving a result off by 1000. Wave behavior matters only for tiny masses. Electron diffraction (Davisson-Germer, 1927) confirmed it. It prepares the way for the Schrodinger wave equation and electron microscopes.
Everyday objects have absurdly small de Broglie wavelengths, but electrons and neutrons have wavelengths near atomic spacing, so their wave nature shows. The interactive lesson shows this as a live animation or chart.
An electron moving at 1.0 x 10^6 m/s has a wavelength of about 0.73 nm, comparable to the spacing of atoms in a crystal.
All matter has wave character with wavelength equal to Planck's constant divided by momentum.
de Broglie Hypothesis is a intermediate topic in Atomic Structure & Periodicity. It builds on the vocabulary of beginner topics in this area.
Study these earlier topics in Atomic Structure & Periodicity first: Bohr Model, Bohr Energy Levels, Limitations of Bohr Model.
The next topics in Atomic Structure & Periodicity are Heisenberg Uncertainty Principle and Wave Function.
Yes. The interactive lesson includes a self-check question on de Broglie Hypothesis, and the Atomic Structure & Periodicity quiz draws on every topic in this area.
de Broglie Hypothesis is topic 48 of 115 in Atomic Structure & Periodicity.