What is the Electronic Configuration of Copper (Cu, Cu+, and Cu2+)?

This article explains the Electronic Configuration of Copper and how to write the Electronic Configuration of Copper atom (Cu).

Electronic Configuration of Copper

Electronic Configuration of Copper Atom (Cu) (Atomic Number 29)

The atomic number of Copper (Cu) = 29

So, let’s start writing the electronic configuration of Copper (Cu) based on the Aufbau Principle. According to Aufbau Principle, “the orbitals are filled up with electrons in order of their increasing energy, i.e., orbital of lowest energy are filled up first, and those with the highest energy are filled up at the end.” The order of the orbital occupancy is shown in the following diagram.

• According to Aufbau Principle, the first two electrons of Copper (Cu) are filled in 1s orbital.
• Then, the next two electrons for Copper (Cu) occupy the 2s orbital.
• And, the next 6 electrons for Copper (Cu) will go to the 2p orbital.
• Then, the next two electrons go in the 3s.
• Further, the next 6 electrons will go to the 3p orbital.
• By following the same rule of the Aufbau Principle, within the remaining 11 electrons, two electrons are placed in the 4s orbital, and 9 electrons are placed in the 3d orbital. Thus, the expected electronic configuration of Copper (Cu) will be as follows:

The expected electronic configuration of Copper (Cu): 1s²2s²2p⁶3s²3p⁶4s²3d⁹

However, half–filled or fully-filled orbitals are more stable due to the symmetrical distribution of electrons. Therefore, one of the 4s² electrons of the Copper (Cu) atom jumps to the 3d⁹ to achieve a fully-filled 3d orbital. Thus, the correct electronic configuration of the Copper (Cu) atom will be as follows:

The correct electronic configuration of Copper (Cu): 1s²2s²2p⁶3s²3p⁶4s¹3d¹⁰

Final Answer

Electronic configuration of Copper (Cu) atom (29): 1s²2s²2p⁶3s²3p⁶4s¹3d¹⁰

This electronic configuration also can be written as [Ar] 4s¹3d¹⁰

Electronic Configuration of Cu⁺ (Atomic Number 28)

The atomic number of Cu⁺ is 28.

The electronic configuration of Cu⁺: 1s²2s²2p⁶3s²3p⁶3d¹⁰

Electronic Configuration of Cu²⁺ (Atomic Number 27)

The atomic number of Cu²⁺ is 27.

The electronic configuration of Cu²⁺: 1s²2s²2p⁶3s²3p⁶3d⁹