Define valency by taking examples of silicon and oxygen.

Answer

 

  • Valency is the combining capacity of an atom.

 

(i) Silicon

 

  • Atomic number = 14
  • Number of electrons = Atomic number = 14
  • Electronic configuration of silicon is 2,8,4
  • Hence, the valence shell has 4 e -
  • It has equal chance of gaining, losing or sharing it's valence electrons in order to achieve octet 
  • In any case the valency of silicon = 4

 

(ii) Oxygen  

 

  • Atomic number = 8
  • Number of electrons = Atomic number = 8
  • Electronic configuration of Oxygen is 2,6
  • Hence, the valence shell has 6 e -
  • If an atom has 6 electrons in its valence shell, it is easier for them to gain 2 e- to achieve an octet
  • Therefore, valency of oxygen = 2

 

  1. Class 9
  2. Chapter 4 Class 9 - Structure of Atom (Term 2)

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CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo