CoachA curly arrow shows the movement of a pair of electrons during a step of a reaction. It starts from the pair that moves, a lone pair or a bond, and ends where the pair goes: on an atom, where it forms a new bond, or on an atom that takes the pair of a bond that breaks.
Examples
Example 40.6 (A first arrow)
A hydrogen ion meets a hydroxide ion . A lone pair of the oxygen forms a bond with the hydrogen ion, which has no electrons: . One arrow, from the lone pair of the oxygen to the ; the charges and become 0 in the water molecule.