Chapter 8: The D-block and F-block Elements

Ans: \[{\text{Cu}}\] lies below hydrogen in electrochemical series and has positive electrode potential. hence cannot liberate hydrogen from acids. 

Both the statements assertion and reason are correct and reason is the correct explanation of assertion. 

Ans: Osmium has the capacity to expands its octet by utilising all the electrons from its 6s and 5d orbitals this results it to attain an oxidation state of +8.

Both the statements assertion and reason are correct but reason is not the correct explanation of assertion. The correct option is B.