Elektronparet

Elektronparet, or the electron pair, is a basic concept in chemistry describing two electrons that share the same region of space, usually within a single orbital or a molecular orbital, and that have opposite spins. According to the Pauli exclusion principle, two electrons occupying the same orbital must have opposite spin, forming a paired arrangement. Electron pairs stabilize atoms and molecules through electrostatic attractions between electrons and nuclei, and through electron–electron interactions that lower overall energy when possible.

In covalent bonding, a bonding pair is the two electrons shared between atoms that constitutes a chemical bond. A lone pair (non-bonding pair) is a pair of electrons that belongs to a single atom and does not participate in bonding. The presence of lone pairs influences molecular geometry via valence shell electron pair repulsion (VSEPR) theory, producing shapes such as water (two lone pairs on oxygen giving a bent shape) and ammonia (one lone pair giving a trigonal pyramidal shape).

In molecular orbital theory, electron pairs can be described as occupied molecular orbitals with opposite spins. Paired electrons form singlet states, while unpaired electrons yield paramagnetic behavior. The concept of electron pairing also explains reaction tendencies, bond lengths, and the reactivity of radicals and ions.