The first 25 years of the twentieth century were momentous for the rapid pace of change in scientists' understanding of the nature of matter. (b) In what ways is de Broglie's hypothesis, as it applies to electrons, consistent with J. J. Thomson's conclusion that the electron has mass? In what sense is it consistent with proposals preceding Thomson's work that the cathode rays are a wave phenomenon?

Key Concepts

de Broglie's Hypothesis

de Broglie's hypothesis posits that particles, such as electrons, exhibit wave-like properties, characterized by a wavelength inversely proportional to their momentum. This duality suggests that electrons can behave both as particles and waves, which is fundamental in quantum mechanics. This concept helps bridge the understanding of electron behavior in atomic structures and supports the idea of quantized energy levels.

Mass of the Electron

J. J. Thomson's experiments led to the discovery of the electron and established that it possesses mass, albeit very small compared to other particles. This finding was crucial in understanding the structure of atoms, as it indicated that electrons could influence atomic behavior and stability. The acknowledgment of the electron's mass is essential for reconciling classical physics with emerging quantum theories.

Wave-Particle Duality

Wave-particle duality is a fundamental principle of quantum mechanics that describes how particles, like electrons, can exhibit both wave-like and particle-like properties. This concept was pivotal in the early 20th century, as it challenged classical physics notions and led to the development of quantum theory. The idea that cathode rays could behave as waves aligns with this duality, providing a framework for understanding electron behavior in various contexts.