How many valence electrons does copper have?

Copper, which has the chemical symbol Cu, is located in group 11 of the periodic table. The electron configuration of copper is [Ar] 3d^10 4s^1. This configuration shows that copper has a total of one electron in its outermost shell, which is the 4s orbital.

In terms of valence electrons, these are the electrons in the outermost shell that are available for bonding and chemical reactions. For copper, while it also has 10 electrons in the 3d sublevel, only the single 4s electron is considered to be a valence electron in this context. Therefore, copper has one valence electron, which plays a crucial role in its ability to conduct electricity and participate in chemical bonds.