Ask a Teacher

Search



what is valency?

The number of valence electrons is the valency of the element.

The valency of an element can also be calculated by finding the number of electrons required to complete octet (8) i.e., 8 - Number of valence electrons = Valency.

Examples :

Ex 1: Determine the valency of oxygen (O - 8).

Solution :

0xygen - 8 : 2, 6    
Valency = 8 - Number of valence electrons= 8 - 6= 2

Ex 2 :Calculate number of valence electrons, the valency and valence shell of an atom whose atomic number is 17.

Solution :

Electron configuration:
 
K     L     M
2      8     7
 
Number of valence electrons = 7
Valency = 8 - 7 = 1
Valence shell = M


comments powered by Disqus