Core electrons

Core electrons are the electrons located in the inner shells of an atom, closest to the nucleus. They are tightly bound and do not typically participate in chemical reactions. These electrons help maintain the structure and stability of the atom. The electrons outside these inner shells—called valence electrons—are the ones involved in bonding and chemical interactions. In essence, core electrons act as a stable core that shields the nucleus, while the valence electrons determine how atoms connect with each other.