Question

What do you understand by the term valency?

Answer 1

Valency

• The number of electrons gained/losed or shared by an atom to take part in a bond formation is called valency.
• When an atom loses electrons, the number of protons become more than the number of electrons and a positive ion will form, that is called a positive valency.
• When an atom attain stability by gaining electrons, the number of electrons become more than the number of protons and a negative ion will form, that is called a negative valency.
• Ceratin elements can share electrons to get a stable electronic configuration like carbon.The electron shared in those cases is the valency of that particular element.
• Taking an example oxygen having electronic configuration $2,6$.
• It accept two electron to attain octect configuration.
• Thus the valency is $2$ which is negative due to gaining of electron.