Question

what is meant by valency

Answer 1

All atoms want to have stability (except the noble gases as they are already stable). This means that they want to have 8 electrons in their last shell.

Thus, an atom either gains electrons (as seen in the case of non-metals) or loses electrons (as in case of metals) to attain this number. This exchange of electrons can occur only between atoms as no electrons are present outside atoms.

Thus number of electrons an atom gets from or loses to other atoms so as to have 8 electrons in their last shell is called valency. The atoms from where it gets or gives away its electrons get bonded with that atom.

Answer 2

combining capacity of an element to form compound is known as valency it's to make a complete octet