?Give three examples of ions that have an electron configuration of \(n d^{6}(n=3,4,5, \ldots)\).

Step 1 of 5) Figure 9.12 shows three examples of how valence-bond theory describes the coming together of two atoms to form a molecule. In the example of the formation of H2, each hydrogen atom has a single electron in a 1s orbital. As the orbitals overlap, electron density is concentrated between the nuclei. Because the electrons in the overlap region are simultaneously attracted to both nuclei, they hold the atoms together, forming a covalent bond. The idea of orbital overlap producing a covalent bond applies equally well to other molecules. In HCl, for example, chlorine has the electron configuration 3Ne43s23p5. All the valence orbitals of chlorine are full except one 3p orbital, which contains a single electron. This 3p electron pairs with the single 1s electron of H to form the covalent bond that holds HCl together (Figure 9.12). Because the other two chlorine 3p orbitals are already each filled with a pair of electrons, they do not participate in the bonding to hydrogen.