What is Lone pair?
[[Image:ParSolitario.png|thumb|right|300px|Lone pairs in [[ammonia]] (A), [[water]] (B) and [[hydrochloric acid]] (C)]] Electrons that remain unbonded to another atom are called lone pairs, while electrons that are bonded between two atoms are called bonding pairs. A '''lone pair''' is a group of two [[electron]]s that are not used in any [[chemical bond|bond]]s between [[atom]]s. They are always in the last shell of an atom, the [[valence electron|valence shell]]. Together with the electrons used in bonding they make up the total number of valence electrons. They are usually high in energy. You can think of a lone pair as a pair of electrons that an atom isn't sharing with anyone else. A lone pair can be used to form new bonds between [[molecule]]s. [[Nucleophile]]s always have a lone pair that is used to attack an [[electrophile]]. Lone pairs are also important for the shape of a molecule. They take more space around an atom than a bonding electron. Lone pairs on a same atom want to be as far away from each other as possible. {{Chemical bonding theory}} [[Category:Theoretical chemistry]]