What is the proper name for SiO2?

Silicon dioxide is the proper name for SiO2 because it accurately reflects the composition of the compound. In this molecular formula, silicon (Si) is combined with two oxygen (O) atoms. The prefix "di-" in "dioxide" indicates that there are two oxygen atoms present.

In nomenclature, the naming convention for binary compounds, which are composed of two different elements, typically involves using Greek prefixes to denote the number of atoms of each element in the molecule. In this case, "di-" signifies two oxygen atoms bonded to a single silicon atom, resulting in the name "silicon dioxide."

The other options, while they might seem plausible, use incorrect prefixes or suggest a different ratio of elements. Silicon tetroxide would imply four oxygen atoms, silicon monoxide would indicate one oxygen atom, and silicon trioxide would refer to three oxygen atoms. Since SiO2 distinctly contains one silicon atom and two oxygen atoms, "silicon dioxide" is the accurate and accepted name.