write the condensed (noble - gas) electron configuration of cu²⁺. for multi - digit superscripts or…

Explanation:

Step1: Determine Cu's atomic number

Copper (Cu) has an atomic number of 29.

Step2: Write Cu's electron - configuration

The electron - configuration of Cu is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}3d^{10}$ (due to the stability of the half - filled 4s and fully - filled 3d subshells).

Step3: Consider $Cu^{2 + }$ ion

When Cu loses 2 electrons to form $Cu^{2+}$, it loses one electron from the 4s orbital and one electron from the 3d orbital.

Step4: Write the noble - gas core

The noble - gas core before 4s and 3d is argon (Ar), which has an atomic number of 18 and electron - configuration $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}$.

Step5: Write the condensed electron - configuration of $Cu^{2+}$

The condensed (noble - gas) electron - configuration of $Cu^{2+}$ is $[Ar]3d^{9}$.

Answer:

$[Ar]3d^{9}$