orbitaltypes

Orbital types refer to categories of atomic orbitals distinguished by their angular momentum, labeled by the azimuthal quantum number l. The principal, widely used types are s (l = 0), p (l = 1), d (l = 2), and f (l = 3), with higher-l types such as g (l = 4) existing in theory. For a given principal quantum number n, l can take values from 0 up to n−1, producing subshells such as 2s, 2p, 3s, 3p, 3d, and so on. Each orbital type contains a set of orbitals with different magnetic quantum numbers m_l, ranging from −l to +l, giving (2l + 1) orbitals per subshell. Each orbital can accommodate two electrons with opposite spin.

Shapes and properties vary by type. s orbitals are spherical and feature no angular nodes; p orbitals have a dumbbell shape and are oriented along three axes; d orbitals have more complex clover or donut-like shapes, totaling five orbitals per set; f orbitals are even more intricate, with seven orbitals per set. The angular nodes equal l, and the total number of radial nodes for a given n and l is n − l − 1.

Electron occupancy follows the Pauli exclusion principle, Hund’s rule, and the Aufbau principle. In multi-electron atoms, energy ordering is influenced by electron–electron interactions, so subshells are filled in a practical sequence that guides chemical behavior. Valence chemistry typically involves s and p orbitals, while d and f subshells become important for transition metals and the lanthanide/actinide series, affecting bonding, magnetism, and spectroscopy.

Orbital types provide a compact framework for describing electron distributions, atomic structure, and the selection rules that govern transitions in atoms and molecules.