Final answer:
Among the given options, CaO (Calcium oxide) contains ionic bonds because it is formed between calcium (a metal) and oxygen (a nonmetal), resulting in the transfer of electrons and the creation of ions that electrically attract each other.
Step-by-step explanation:
The question is which compound contains ionic bonds. Ionic bonds generally form between a metal and a nonmetal, resulting in the transfer of electrons and formation of ions that attract each other due to their opposite charges. Let's examine each option provided:
- NO₂ (Nitrogen dioxide): This compound is made up of nitrogen and oxygen, which are both nonmetals, hence NO₂ is not an ionic compound.
- Cl₃: This formula is not representative of a stable compound; chlorine is a nonmetal and typically forms covalent bonds with other nonmetals or itself in the form of Cl₂.
- NO (Nitric oxide): Like NO₂, this compound consists of two nonmetals and thus, forms covalent bonds.
- CaO (Calcium oxide): Calcium is a metal, while oxygen is a nonmetal. The calcium loses two electrons to become Ca²⁺ and oxygen gains two electrons to become O²⁻, forming the ionic compound CaO.
Thus, the compound that contains ionic bonds is option 4) CaO.