What is the chemical name for the compound represented by SO3?

The correct name for the compound represented by SO3 is sulfur trioxide. This nomenclature follows the rules for naming covalent compounds, where the prefix indicates the number of each type of atom present in the molecule. In this case, "sulfur" refers to the sulfur atom, and "trioxide" indicates that there are three oxygen atoms bonded to it. The prefix "tri-" specifically denotes the presence of three oxygen atoms in the formula.

Other names in the choices do not accurately reflect the composition of the compound. "Sulfur oxytree" is not a recognized term in chemical nomenclature. "Sulfur hexafluoride" refers to a completely different compound with the formula SF6, which contains six fluorine atoms. "Sulfur dioxide" indicates the presence of only two oxygen atoms, represented by the formula SO2, which is not applicable for SO3. Thus, sulfur trioxide is the precise and correct chemical name for this compound.