What is the chemical name for WO₃?

The chemical name for WO₃ is tungsten oxide. In this compound, tungsten (W) has a valence of +6, which corresponds with the oxidation state indicated by the formula. The oxide part of the name comes from the presence of oxygen in the formula, with three oxygen atoms combined with a single tungsten atom.

Tungsten is often referred to by its traditional name, 'wolfram,' particularly in some European countries, which leads to another possible name for WO₃ as wolfram trioxide. However, the more commonly accepted and universal name in chemical nomenclature is tungsten oxide.

The other names listed do not accurately represent WO₃. For instance, "oxy tungsten" does not follow the standard naming conventions and is ambiguous as it could suggest various oxides of tungsten. Similarly, "tungsten dioxide" would refer to WO₂, which consists of tungsten in a +4 oxidation state. Hence, tungsten oxide is the most appropriate and widely recognized name for WO₃.