An electron orbital is a region of space around the nucleus of an atom where electrons are most likely to be found. It is often represented as a cloud-like shape.
The shape of an electron orbital is determined by the energy level and sublevel of the electron. The energy level refers to the distance from the nucleus, while the sublevel refers to the shape of the orbital (s, p, d, or f).
An orbital can hold a maximum of two electrons, as long as they have opposite spins.
An atomic orbital refers to the space around a single atom, while a molecular orbital refers to the space around a molecule. Molecular orbitals are formed by the combination of atomic orbitals from different atoms.
The rows of the periodic table correspond to the energy levels of the electrons, while the columns correspond to the sublevels. This helps to organize the elements based on their electron configurations and properties.