To determine which of the given molecules is considered an ionic compound, it is essential to understand the nature of ionic and covalent bonds.
1. O₂ (Oxygen Gas):
- Oxygen gas consists of two oxygen atoms bonded together.
- These atoms share electrons equally, forming a covalent bond.
2. K₂S₃ (Potassium Sulfide):
- Potassium (K) is a metal, and sulfur (S) is a non-metal.
- Ionic bonds typically form between metals and non-metals.
- Potassium donates electrons to sulfur, resulting in positive potassium ions (K⁺) and negative sulfide ions (S²⁻).
- This forms an ionic compound.
3. H₂O (Water):
- Water consists of hydrogen and oxygen atoms bonded together.
- The atoms share electrons, but the sharing is unequal due to oxygen's higher electronegativity.
- This results in a polar covalent bond.
4. NH₃ (Ammonia):
- Ammonia consists of nitrogen and hydrogen atoms bonded together.
- The atoms share electrons, with nitrogen holding the shared electrons more closely due to its higher electronegativity.
- This is also a polar covalent bond.
Based on this analysis, the molecule that is considered an ionic compound is:
K₂S₃ (Potassium Sulfide)
Thus, the correct answer is K₂S₃.
