How to Correctly Name the Following Compounds: Na3P and Al2S3?

To correctly name the compounds Na₃P and Al₂S₃, we must consider the rules of nomenclature for ionic compounds.

1. **Na₃P**: This compound comprises sodium (Na) and phosphorus (P). Sodium is an alkali metal and carries a +1 charge, while phosphorus in this compound acts as a phosphide ion with a -3 charge. When naming this compound, we call the metal first, followed by the non-metal with an ‘ide’ suffix. Thus, Na₃P is called Sodium Phosphide.

2. **Al₂S₃**: This compound contains aluminum (Al) and sulfur (S). Aluminum typically has a +3 charge, whilst sulfur forms a sulfide ion with a -2 charge. Again, we name the metal first, followed by the non-metal with the ‘ide’ suffix. Therefore, Al₂S₃ is named Aluminum Sulfide.

In summary, the correct names for these compounds are Sodium Phosphide for Na₃P and Aluminum Sulfide for Al₂S₃.