Step 1: Understanding the Concept:
Coinage metals are elements that were historically used for making coins. They belong to Group 11 (IB) of the periodic table.
Step 2: Detailed Explanation:
The coinage metals are Copper (\( \text{Cu} \), \( Z=29 \)), Silver (\( \text{Ag} \), \( Z=47 \)), and Gold (\( \text{Au} \), \( Z=79 \)).
Let's look at the electronic configuration of Copper:
\( \text{Cu} (Z=29) \): \( [\text{Ar}] 3\text{d}^{10} 4\text{s}^{1} \)
Similarly for Silver:
\( \text{Ag} (Z=47) \): \( [\text{Kr}] 4\text{d}^{10} 5\text{s}^{1} \)
And for Gold:
\( \text{Au} (Z=79) \): \( [\text{Xe}] 4\text{f}^{14} 5\text{d}^{10} 6\text{s}^{1} \)
In all these cases, the outermost configuration is \( \text{(n} - 1)\text{d}^{10} \text{ns}^{1} \). This exceptional configuration (instead of the expected \( \text{d}^{9} \text{s}^{2} \)) is due to the extra stability provided by a completely filled d-subshell.
Step 3: Final Answer:
The configuration is \( \text{(n} - 1)\text{d}^{10}\text{ns}^{1} \).