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Chemical Bonding and Molecular Structure — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistryChemical Bonding and Molecular Structure5 Marks
Question
Define octet rule. Write its significance and limitations.
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Answer

Octet rule: Atoms of elements combine with each other in order to complete their respective octets so as to acquire the stable gas configuration.Significance: It helps to explain why different atoms combine with each other to form ionic compounds or covalent compounds.
Limitations of Octet rule:
  • According to Octet rule, atoms take part in chemical combination to achieve the configuration of nearest noble gas elements. However, some of noble gas elements like Xenon have formed compounds with fluorine and oxygen. For example: $\mathrm{XeF}_2, \mathrm{XeF}_4$ etc.
    Therefore, validity of the octet rule has been challenged.
  • This theory does not account for shape of molecules.

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