# Electronic configuration of copper [Z = 29] is – (a) [Ar] 3d94s2 (b) [Ar] 3d94s14p1 (c) [Ar] 3d104s1 (d) [Ar] 3d84s24p1

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Updated on: September 25th, 2023

The electronic configuration of copper [Z = 29] is [Ar] 3d10 4s1. Its electronic configuration is the configuration of electrons in an atom’s electronic levels. The placement of the electrons is determined by their energies and available space. While placing the electrons in an atom, we adhere to a few sets of laws.

## Set of Laws for Electronic Configuration

Aufbau principle:

• According to this, the lower-energy atomic orbitals are filled first.
• The electron then moves to the higher atomic energy levels to occupy them.
• The electronic configuration of atoms in their ground state is written using this rule.
• The electrons may leave the lower energy state and transition to a higher energy level when in the excited state.
• Atomic orbitals are filled in the following order: 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p.
• As a result, the atomic orbital with the lower (n + l) value will have less energy, where n is the primary quantum number and l is the azimuthal quantum number.

Pauli’s exclusion principle:

• The four quantum numbers n, m, l, and s describe one electron.
• According to Pauli’s exclusion principle, each electron must have a distinct combination of these four quantum numbers.
• The quantum numbers of any two electrons cannot be identical.
• To put it simply, we can say that an orbital can hold up to two electrons at most, and they should have opposite spins ( + ½, – ½ ).

Hund’s rule of maximum spin multiplicity:

• The subshell will first be occupied by a single electron before being filled with electrons of the same energy, or degeneracy.
• When every subshell has been occupied solely, electron pairing will begin.
• According to this criterion, the maximal spin should be preserved while adding electrons to a subshell.
• The most stable state is produced by the largest spin state, which also entails the most exchange energy.

Element Copper(Cu):

• Element Cu has an atomic number of 29.
• The electronic configuration should be 1s2 2s2 2p6 3s2 3p6 4s2 3d9.
• Due to their lower energy or greater stability, the partially filled and fully filled configurations (d5d10f7f14) are the cause of this.
• However, the actual electronic configuration is 1s2 2s2 2p6 3s2 3p6 4s1 3d10 or [Ar] 3d10 4s1
• Thus, in order for the 4d orbitals to have a fully filled configuration, the 5s electrons enter them in order for them to become stable.
• The electron can smoothly go from the lower energy 4s orbital to the higher energy 3d orbital.
• The minimal energy difference between the 4s and 3d orbitals makes this possible.

Therefore, electronic configuration of copper [Z = 29] is [Ar] 3d10 4s1

Summary:

## Electronic configuration of copper [Z = 29] is – (a) [Ar] 3d94s2 (b) [Ar] 3d94s14p1 (c) [Ar] 3d104s1 (d) [Ar] 3d84s24p1

The electronic configuration of copper [Z = 29] is [Ar] 3d10 4s1. The arrangement of electrons in an atom’s electronic levels is known as its electronic configuration.

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