The behavior of electrons in an atom is described by quantum mechanics, which provides us with a statistical and probabilistic description rather than a deterministic one. According to quantum mechanics, we cannot precisely determine the position and velocity of an electron simultaneously. However, we can make probabilistic predictions about the electron's behavior and its distribution of probable locations.
The most commonly used model to describe the behavior of electrons in atoms is the quantum mechanical model, which is based on the concept of electron orbitals. Electron orbitals are regions of space where there is a high probability of finding an electron.
Experimental evidence, such as spectroscopy and electron diffraction, supports the existence of these electron orbitals and the idea that electrons occupy specific energy levels around the nucleus. Spectroscopy involves studying the interaction of atoms or molecules with light, while electron diffraction experiments study the behavior of electrons as they pass through a crystalline material.
By analyzing the patterns observed in spectroscopy and electron diffraction experiments, scientists have determined that electrons occupy discrete energy levels in atoms and move in wave-like patterns described by orbitals. These orbitals can be thought of as "clouds" or regions of space where there is a high probability of finding an electron. The exact location of an electron within an orbital is uncertain, but we can predict the probability of finding it within a certain volume of space.
It's important to note that the concept of electrons "moving" around the nucleus in a classical sense is not accurate. Electrons do not follow well-defined paths or orbits like planets around the Sun. Instead, they exist in a superposition of states and can be described as both particles and waves. The precise behavior of electrons is described by complex mathematical equations known as wave functions, which give us information about the probability distribution of finding an electron at a particular location.
In summary, we infer the presence and behavior of electrons in atoms based on experimental observations and the predictions of quantum mechanics. While we cannot directly observe the motion of an electron around the nucleus, we can determine the probability of finding an electron in certain regions of space based on experimental evidence and mathematical models.