NaCl does not contain molecules. NaCl is an ionic compound which is composed ions( Na+ and Cl-) that are attracted to each other because of their opposite charges. The chemical formula representation of an ionic compound is called a formula unit. Molecular compounds are covalent compounds which are made up of atoms sharing some of their valence electrons for stability.
Further Explanation:
Ionic Compounds
Compounds that are made up of a metal and a non-metal are called ionic compounds. The metal transferred one or more valence electrons to the non-metal atom resulting in the formation of charged particles called the metal cation and the non-metal anion. The cation is positively charged and the anion is negatively charged. Because of their opposite charges, the ions tend to attract each other and move closer to each other forming the crystal lattice or the 3-D arrangement of an ionic compound. The simplest ratio of the ions in a crystal lattice is called the formula unit of the ionic compound and is used as the chemical formula of the ionic compound.
Covalent Compounds
Covalent compounds are made up of two or more non-metals that are chemically combined.The non-metal atoms in the compound share valence electrons to be stable.Covalent compounds are also called molecules which are groups of 2 or more atoms that are chemically bonded to each other.
Among the choices only NaCl is an ionic compound:
CO2 - carbon, C (non-metal) ; oxygen, O (non-metal) --> COVALENT
H2 - hydrogen, H (non-metal) --> COVALENT
NaCl - sodium, Na (metal) ; chlorine, Cl (non-metal) --> IONIC
H2O - hydrogen, H (non-metal); oxygen, O (non-metal) --> COVALENT
Learn More:
Learn more about chemical formula Learn more about molecular formula Learn more about ions
Keywords: ionic compound, covalent compounds, molecule
