Check sibling questions

Define valency by taking examples of silicon and oxygen.



  • 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


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CA Maninder Singh is a Chartered Accountant for the past 12 years and a teacher from the past 16 years. He teaches Science, Accounts and English at Teachoo