Chemistry

Question Analysis
This question evaluates the student's understanding of electron configurations for ions and the order in which electrons are removed from the atom.

Key Concept Explanation
When forming an ion, electrons are typically removed from the outermost (highest energy) subshell first. For transition metals like copper, the 4s electrons are removed before the 3d electrons.

Step-by-step Solution
1. Determine the electron configuration of neutral copper (Cu, atomic number 29): [Ar] 4s¹ 3d¹⁰.
2. Remove the 4s electron first to form Cu⁺: [Ar] 3d¹⁰.
3. Remove one 3d electron to form Cu²⁺: [Ar] 3d⁹.
4. T...