Step 1: Understanding the Concept:
First Ionization Enthalpy is the energy required to remove the first electron from an isolated gaseous atom. It generally increases across a period due to increasing nuclear charge and decreasing atomic size.
Step 3: Detailed Explanation:
Across the \(3d\) series (\(Sc\) to \(Zn\)), the effective nuclear charge increases.
Zinc (\(Zn\)) is the last element of the \(3d\) transition series.
The electronic configuration of \(Zn\) is \([Ar] 3d^{10} 4s^2\).
Both the \(3d\) and \(4s\) subshells are completely filled, providing extra stability.
Removing an electron from the stable, fully-filled \(4s^2\) configuration of \(Zn\) requires significantly more energy compared to other elements in the series.
Step 4: Final Answer:
Zinc (\(Zn\)) has the highest first ionization enthalpy among the given elements.