The valencies of aluminium and chlorine in the compound AlCl3 are
3, 1
The valencies of aluminium and chlorine in the compound AlCl3 respectively are 3,1. Valency is the combining power of an element. The valency of an element is related to how many electrons are in the outer shell. Al has three elecrons in its outermost shell and thus has a valency of 3, whereas Cl has 7 electons in its outermost orbit and thus requires 1 more electron to complete its octet configuration and thus has a valency of 1. It is important to note that for metals, valency is the number of electrons it needs to release to form an octet configuration. Similarly, for non-metals, valency is given by the number of electrons to be added to complete the octet configuration.