Subshell Electronic Configuration

The (n-1)d 10 ns 2 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] 3d 10 4s 1 . It does not have the (n-1)d 10 ns 2 configuration. Zn (Zinc): The electronic configuration of Zn is [Ar] 3d 10 4s 2 . It also does not have the (n-1)d 10 ns 2 configuration. Why are the other options incorrect? Option (A): Cd (Cadmium) has the configuration [Kr] 4d 10 5s 2, which fits the (n-1)d 10 ns 2 pattern. Option (B): Hg (Mercury) has the configuration [Xe] 4f 14 5d 10 6s 2, which fits the (n-1)d 10 ns 2 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)d 10 ns 2 pattern. Conclusion: The correct answer is (D) Cu, Zn because neither copper nor zinc has the (n-1)d 10 ns 2 configuration in their elementary state.

Chapter Questions
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