Among Group 16 elements, which one does NOT show –2 oxidation state?

The correct option is Po (Polonium).

Step-by-Step Explanation:

1. Group 16 of the periodic table, also known as the oxygen family or chalcogens, consists of the elements: Oxygen (O), Sulfur (S), Selenium (Se), Tellurium (Te), and Polonium (Po).

2. The general valence shell electronic configuration of Group 16 elements is ${\mathrm{ns}}^2{\mathrm{np}}^4$. To achieve a stable noble gas configuration (octet), these elements need to gain or share two electrons, which typically results in an oxidation state of -2.

3. As we move down the group from Oxygen to Polonium, the atomic size increases and the electronegativity of the elements decreases significantly. Due to the decrease in electronegativity, the tendency to attract and hold two negative charges (to show a -2 oxidation state) decreases down the group.

4. Polonium (Po) is a heavy, radioactive metalloid located at the bottom of Group 16. It has a very low electronegativity and a strong metallic character. Because of its metallic nature and the inert pair effect, polonium does not show a negative oxidation state like -2. Instead, it exhibits positive oxidation states, primarily +2 and +4.

Therefore, among the given Group 16 elements, Polonium (Po) is the one that does not show a –2 oxidation state.