The (n−1)d10ns2 configuration is typical for transition metals in their ground state, where 'n' represents the outermost shell.
Why is option (D) correct?
- Cu (Copper): The electronic configuration of Cu is [Ar] 3d104s1. It does not have the (n−1)d10ns2 configuration.
- Zn (Zinc): The electronic configuration of Zn is [Ar] 3d104s2. It also does not have the (n−1)d10ns2 configuration.
Why are the other options incorrect?
- Option (A): Cd (Cadmium) has the configuration [Kr] 4d105s2, which fits the (n−1)d10ns2 pattern.
- Option (B): Hg (Mercury) has the configuration [Xe] 4f145d106s2, which fits the (n−1)d10ns2 pattern.
- Option (C): Cn (Copernicium) is a synthetic element and its configuration is not well established, but it is likely to have a configuration that fits the (n−1)d10ns2 pattern.
Conclusion: The correct answer is (D) Cu, Zn because neither copper nor zinc has the (n−1)d10ns2 configuration in their elementary state.