Which of the following elements does not belong to group 16 of the periodic table? 

Phosphorus

The correct answer is option 2. Phosphorus.

The periodic table is organized into groups or families based on similar chemical properties. Group 16 elements are commonly known as the oxygen group or chalcogens. They include oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and polonium (Po).

Elements in Group 16 have six valence electrons and share common characteristics such as the ability to form compounds with oxygen (oxides) and the tendency to show multiple oxidation states. Oxygen is a diatomic gas (O₂), sulfur forms compounds like hydrogen sulfide (H₂S), selenium and tellurium exhibit similar chemical behavior, and polonium is a radioactive element.

Phosphorus, on the other hand, belongs to Group 15, also known as the nitrogen group or pnictogens. It includes nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). Group 15 elements typically have five valence electrons and share some common properties, but they are distinct from the Group 16 elements.