The Correct Answer and Explanation is:
The correct formula for disulfur tetrabromide is S₂Br₄.
This chemical name provides all the information needed to write its formula by following the standard nomenclature rules for binary covalent compounds. These are compounds formed between two nonmetal elements, which in this case are sulfur (S) and bromine (Br).
The naming system uses Greek prefixes to specify the exact number of atoms of each element present in a single molecule. Here is a breakdown of the name “disulfur tetrabromide”:
- Disulfur: The prefix “di” means two. This indicates that there are two atoms of the first element, sulfur. Therefore, this part of the name translates to S₂ in the chemical formula.
- Tetrabromide: The prefix “tetra” means four. This indicates that there are four atoms of the second element, bromine. The element name “bromine” is changed to the suffix “bromide” because it is the second, more electronegative element in the compound. This part of the name translates to Br₄ in the chemical formula.
When you combine these two parts, you simply write the element symbols in the order they appear in the name and use the numbers indicated by the prefixes as subscripts. The subscript is a small number written to the lower right of the element’s symbol. This process gives you the final chemical formula: S₂Br₄.
This prefix system is distinct from the one used for ionic compounds, which involves balancing the electrical charges of the ions to determine the formula’s ratios. For covalent compounds like disulfur tetrabromide, the prefixes directly tell you the composition of the molecule, making the translation from name to formula a straightforward process.
