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Question
Assertion: The highest oxidation state of osmium is +8.
Reason: Osmium is a 5d-block element.
Options
Both assertion and reason are true, and reason is the correct explanation of the assertion.
Both assertion and reason are true but reason is not the correct explanation of assertion.
Assertion is not true but reason is true.
Both assertion and reason are false.
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Solution
Both assertion and reason are true but reason is not the correct explanation of assertion.
Explanation:
Osmium has the capacity to expands its octet by utilising all the electrons from its 6s and 5d orbitals this results it attaining an oxidation state of +8.
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