To determine the correct suffix for the compounds [tex]\( \text{FeS} \)[/tex], [tex]\( \text{NaCl} \)[/tex], and [tex]\( \text{Al}_3\text{O}_2 \)[/tex], we need to look at the standard naming conventions for these types of chemical compounds, often referred to as binary compounds.
1. FeS (Iron(II) sulfide):
- Fe refers to Iron and S refers to Sulfur.
- Sulfur forms a binary compound with Iron.
- The name for this compound ends with '-ide' because sulfur becomes sulfide in nomenclature.
2. NaCl (Sodium chloride):
- Na refers to Sodium and Cl refers to Chlorine.
- Chlorine forms a binary compound with Sodium.
- The name for this compound ends with '-ide' because chlorine becomes chloride.
3. Al_3O_2 (Aluminum oxide):
- Al refers to Aluminum and O refers to Oxygen.
- Oxygen forms a binary compound with Aluminum.
- The name for this compound ends with '-ide' because oxygen becomes oxide.
All three of these compounds end with the suffix '-ide'. Therefore, the correct answer is:
A. -ide
