Cu electron configuration refers to the arrangement of electrons within a copper atom. It consists of 29 electrons distributed in orbitals around the nucleus. The configuration can be represented as [Ar] 3d¹⁰ 4s¹, where [Ar] represents the electron configuration of argon (1s² 2s² 2p⁶ 3s² 3p⁶), followed by the 3d subshell with 10 electrons, and the 4s subshell with 1 electron. This configuration plays a crucial role in determining the chemical properties and behavior of copper, influencing its reactivity, bonding characteristics, and physical properties.