The current model of the atom is known as the quantum mechanical model or the electron cloud model. This model is an improvement upon the earlier atomic models proposed by scientists such as J.J. Thomson, Ernest Rutherford, and Niels Bohr.
According to the quantum mechanical model, an atom consists of a central nucleus made up of protons and neutrons, surrounded by a cloud or "orbitals" where electrons are likely to be found. The nucleus carries a positive charge due to the protons it contains, while the electrons carry a negative charge. The neutrons have no charge and contribute to the mass of the atom.
The behavior and properties of electrons in the atom are described by quantum mechanics, a branch of physics that deals with the behavior of particles at the atomic and subatomic levels. According to quantum mechanics, electrons do not move in fixed, defined orbits like planets around the sun, as suggested by the earlier Bohr model. Instead, they exist in regions around the nucleus called orbitals or electron clouds, which represent the probability of finding an electron at a particular location.
These orbitals are described by mathematical equations called wave functions, which provide information about the energy levels and shapes of the orbitals. The electron cloud model represents the probability distribution of finding an electron in a particular region around the nucleus. The more dense the cloud, the higher the probability of finding an electron in that region.
The quantum mechanical model also incorporates the concept of electron energy levels or shells. Electrons occupy specific energy levels around the nucleus, and each level can contain a specific number of electrons. The innermost shell is closest to the nucleus and can hold a maximum of two electrons, while the subsequent shells can hold more. However, it's important to note that electrons do not occupy specific orbits within these shells but rather exist in the electron cloud associated with each energy level.
Overall, the quantum mechanical model provides a more accurate and comprehensive understanding of the behavior of atoms and their constituent particles compared to the earlier models. It takes into account the wave-like nature of particles and the probabilistic nature of electron positions, allowing for a more detailed description of atomic properties and interactions.