Answer the following question:
 
Define valency by taking example of fluorine.
 
Valency or valence refers to an atom's ability to to form a chemical compound.
  
Example:

Atomic number of fluorine \(=\) \(9\)

Electronic configuration of fluorine \(=\)

In fluorine atom, the valence electrons are . To complete its octet, electrons are required. Hence, the valency of fluorine is .