2pOrbitale

2p orbitals are the p-type atomic orbitals of the second electron shell, corresponding to the principal quantum number n = 2 and angular momentum quantum number l = 1. The 2p subshell consists of three degenerate orbitals, commonly labeled 2p_x, 2p_y, and 2p_z, each capable of holding two electrons. Together they accommodate up to six electrons.

In terms of quantum properties, the p orbitals have one angular node and, for n = 2 and l = 1, zero radial nodes. The three orbitals are associated with the magnetic quantum numbers m_l = -1, 0, +1, which in practice are often represented as the Cartesian set p_x, p_y, and p_z. The shapes are dumbbell-like lobes oriented along their respective axes, with a nodal plane perpendicular to the orbital’s axis passing through the nucleus.

Energy and occupancy considerations place the 2p set after the 2s subshell in most atoms. In isolated atoms, the 2s orbital is typically lower in energy than the 2p set, but electron-electron interactions can complicate ordering in some cases. The 2p orbitals become the valence orbitals for elements in the second period from boron through neon, contributing to chemical bonding and reactivity. They are more extended than inner-shell orbitals and play a central role in determining molecular structure and bonding patterns.

In molecules, the 2p orbitals participate in sigma and pi bonding. For example, in diatomic molecules, 2p_z can form a sigma interaction along the bond axis, while 2p_x and 2p_y form degenerate pi interactions. Hybridization with 2s orbitals (such as sp, sp2, and sp3) combines these orbitals to form new bonding frameworks.