QNEET-2024-Ch-9: NEET 2024 Chemistry - Class 12 NEET-2024-Ch-9 Solution: Among Group 16 elements which one does NOT show -2 oxidation…

Core Concept & Governing Principle Group 16 (chalcogen) elements possess six valence electrons. By gaining two electrons they achieve a noble‑gas configuration, so the –2 oxidation state is the most common. The stability of a particular oxidation state depends on the element’s metallic‑non‑metallic character and relativistic effects for heavy members. Step 1: List the Group 16 elements. O, S, Se, Te, Po. Step 2: Identify the typical oxidation states of each element. - Oxygen (O): highly electronegative; almost exclusively –2 (e.g., H₂O, CO₂). - Sulfur (S): –2 in sulfides (e.g., Na₂S) and also higher positive states (+4, +6). - Selenium (Se): –2 in selenides (e.g., H₂Se) and also +4, +6. - Tellurium (Te): –2 in tellurides (e.g., H₂Te) and also +4, +6. - Polonium (Po): being a heavy metalloid with pronounced metallic character, the stable oxidation states are +2 and +4 (e.g., PoCl₂, PoO₂). The –2 state is extremely rare and not observed in stable compounds. Step 3: Compare the occurrence of the –2 state. All lighter chalcogens (O, S, Se, Te) readily form –2 anions (O²⁻, S²⁻, Se²⁻, Te²⁻). Polonium does not form a stable Po²⁻ ion; its chemistry is dominated by Po²⁺ and Po⁴⁺. Step 4: Conclude which element does **not** show the –2 oxidation state. The only Group 16 element that fails to exhibit a stable –2 oxidation state is polonium (Po). Final Conclusion & Correct Option Polonium does not commonly show the –2 oxidation state. **Option D**.