Which chemical formula indicates the presence of more than one element?

The presence of more than one element in a chemical formula signifies that the compound is composed of different types of atoms. In this case, each of the provided options includes at least two different elements in their formulas.

For sodium hydride, represented as NaH, there are two elements: sodium (Na) and hydrogen (H). The presence of both elements indicates a binary compound.

Silicon dioxide, or SiO2, is composed of silicon (Si) and oxygen (O), making it another example of a compound that contains more than one element. This compound consists of one silicon atom and two oxygen atoms.

Potassium oxide, K2O, once again consists of two elements: potassium (K) and oxygen (O). The subscript '2' indicates that there are two potassium atoms partnered with one oxygen atom.

Since each of these chemical formulas contains more than one element, the correct answer correctly identifies that all options represent compounds formed from different elements. This demonstrates the fundamental principle in chemical nomenclature that different elements combine to form compounds, which is accurately reflected in each of the choices provided.