Particles and waves are two different ways to describe the behavior of physical entities, and it's not accurate to say that particles become waves when they get smaller. Instead, the behavior of particles can exhibit both particle-like and wave-like properties, depending on the experimental setup and observation.
In the realm of quantum mechanics, particles such as electrons, protons, and even larger entities like atoms and molecules can exhibit wave-particle duality. This means that they can exhibit characteristics of both particles and waves under certain circumstances. The wave-particle duality was first proposed by Louis de Broglie and later experimentally verified through experiments like the double-slit experiment.
When studying the behavior of particles on a microscopic scale, such as atoms or subatomic particles, their behavior is often described by wave functions, which are mathematical descriptions that represent the probability distribution of finding the particle in different states. The wave function can exhibit wave-like properties, such as interference and diffraction, which are characteristic of waves.
However, it's important to note that particles are not literally transforming into waves or vice versa. The wave-particle duality is a conceptual framework that helps describe the behavior of particles in quantum mechanics. The choice of whether to describe a particle as a wave or a particle depends on the experimental context and the specific properties being observed.