Elektronfelépítés

Elektronfelépítés, often translated as electron configuration, describes the arrangement of electrons within an atom's electron shells and subshells. It is a fundamental concept in chemistry and physics, explaining an atom's chemical behavior and its position in the periodic table. Electrons occupy specific energy levels, also known as shells, and within these shells, they reside in subshells denoted by s, p, d, and f orbitals. Each orbital can hold a maximum of two electrons, with opposite spins.

The filling of these orbitals follows specific rules, primarily the Aufbau principle, Hund's rule, and the Pauli exclusion principle. The Aufbau principle states that electrons fill orbitals starting from the lowest energy levels. Hund's rule dictates that electrons will singly occupy each orbital within a subshell before pairing up. The Pauli exclusion principle asserts that no two electrons in an atom can have the same set of four quantum numbers, meaning each orbital can hold at most two electrons with opposing spins.

Electron configurations are represented using a shorthand notation, such as 1s²2s²2p⁶ for Neon. The superscripts indicate the number of electrons in each subshell. Understanding electron configurations is crucial for predicting an element's reactivity, ionization energy, and electron affinity, and it forms the basis for chemical bonding theories. Deviations from the expected filling order occur due to the special stability of half-filled and fully-filled subshells.