Question

The element having \([Ar]3d^{10}4s^1\) electronic configuration is

• A. Cu
• B. Zn
• C. Cr
• D. Mn

Hint:

Copper (Cu) has an electron configuration of \( [Ar] 3d^{10} 4s^1 \), which is an exception to the general electron configuration rule due to stability gained by a filled 3d subshell.

Answer 1

The Correct Option is A

To address the problem, the element exhibiting the electronic configuration [Ar]3d\(^{10}\)4s\(^1\) must be identified.

1. Configuration Analysis:
The [Ar] designation signifies the electron configuration of argon, specifically 1s\(^2\)2s\(^2\)2p\(^6\)3s\(^2\)3p\(^6\), totaling 18 electrons. The subsequent [Ar]3d\(^{10}\)4s\(^1\) portion details:
- 3d\(^{10}\): Ten electrons occupy the 3d subshell.
- 4s\(^1\): One electron resides in the 4s subshell.
The cumulative electron count is 18 (from [Ar]) + 10 (from 3d) + 1 (from 4s) = 29 electrons.

2. Element Identification:
In a neutral atom, the number of electrons is equivalent to the atomic number. An element possessing 29 electrons has an atomic number of 29, which corresponds to copper (Cu) on the periodic table.

3. Configuration Verification:
Copper (Cu, atomic number 29) displays the expected ground state configuration. Following the [Ar] noble gas core, the 4s and 3d orbitals are populated. Generally, for transition metals, the 4s orbital is filled prior to the 3d. However, copper represents an anomaly:
- Anticipated: [Ar]4s\(^2\)3d\(^9\)
- Observed: [Ar]4s\(^1\)3d\(^{10}\)
This deviation arises from the enhanced stability of a completely filled 3d subshell (3d\(^{10}\)) compared to a partially filled one. Consequently, an electron from the 4s orbital migrates to the 3d orbital, resulting in the configuration [Ar]3d\(^{10}\)4s\(^1\), which aligns with the provided configuration.

Conclusion:
The element characterized by the electronic configuration [Ar]3d\(^{10}\)4s\(^1\) is copper (Cu).