Show the formation of aluminium ion.( Atomic number of aluminium = 13).
Definition of valency.
The number of valence electrons lost or gained by an atom in order to attain stability is called valency.
The atomic number of aluminium = 13
Electronic configuration = 2,8,3
since aluminium has three electron in its outermost shell, it does not have stable electronic configuration.
Aluminium loses its three electrons and achieve the stable configuration as 2,8.
An aluminium atom() has 13 protons and 13 electrons. On losing one electron, it becomes an aluminium ion().