* Covalent Bonds: Occur when atoms share electrons to achieve a stable electron configuration. Covalent bonds typically form between nonmetals.
* Ionic Bonds: Occur when one atom (typically a metal) loses electrons to become a positively charged ion, and another atom (typically a nonmetal) gains those electrons to become a negatively charged ion. These oppositely charged ions then attract each other.
Let's analyze each compound:
* KCl (Potassium Chloride): Potassium (K) is a metal, and chlorine (Cl) is a nonmetal. This indicates an ionic bond.
* CO (Carbon Monoxide): Carbon (C) and oxygen (O) are both nonmetals. This indicates a covalent bond.
* RbBr (Rubidium Bromide): Rubidium (Rb) is a metal, and bromine (Br) is a nonmetal. This indicates an ionic bond.
* BeO (Beryllium Oxide): Beryllium (Be) is a metal, and oxygen (O) is a nonmetal. This indicates an ionic bond.
Therefore, the only molecule with a covalent bond is CO (Carbon Monoxide).
