2p6

2p6 is the electron configuration notation indicating that the second principal energy level’s p subshell is fully occupied by six electrons. In atomic structure, the p subshell consists of three degenerate orbitals (px, py, pz), and each orbital can hold up to two electrons with opposite spins, for a maximum of six electrons in 2p.

This configuration occurs after the 1s and 2s subshells have been filled, yielding the closed-shell arrangement 1s2 2s2 2p6 for certain elements. The most familiar example is neon (Ne, atomic number 10), whose electronic structure includes exactly 2p6 as part of its outer shell. A filled 2p subshell contributes to overall atomic stability and low chemical reactivity, a hallmark of noble gases.

In terms of properties, a 2p6 configuration implies there are no unpaired electrons in the second shell’s p subshell, making the atom diamagnetic. It also correlates with relatively high ionization energy and a reluctance to form bonds under ordinary conditions, as seen in neon and other noble gases with similarly completed subshells in higher periods (such as 3p6 for argon, 4p6 for krypton, etc.).

In chemical context, 2p6 is a key indicator of a closed-shell atom in the second energy level and helps explain periodic trends in reactivity and spectroscopy. It is specifically associated with neon among common elements, while the concept extends to any atom whose second-shell p subshell is fully filled.