Which group in the periodic table is known as chalcogens? 

Group-16

The correct answer is option 2. Group-16.

The chalcogens are a group of elements located in Group 16 of the periodic table, also known as the oxygen group. This group includes oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and polonium (Po).

Here are some key characteristics and properties of the chalcogens:

1. Valence Electrons: Elements in Group 16 typically have six valence electrons, meaning they have six electrons in their outermost shell. This configuration gives them a strong tendency to gain two electrons to achieve a stable noble gas configuration of eight valence electrons.

2. Chemical Reactivity: Chalcogens are reactive nonmetals. Oxygen, for example, readily reacts with most elements, forming oxides. Sulfur is known for forming sulfides, while selenium, tellurium, and polonium also form compounds with metals, known as selenides, tellurides, and polonides, respectively.

3. Physical States:  Chalcogens exhibit various physical states at room temperature. Oxygen and sulfur are gases, selenium is a semimetal, tellurium is a metalloid, and polonium is a radioactive metal.

4. Biological Importance:  Chalcogens play crucial roles in biological systems. For instance, oxygen is essential for respiration in animals and is a component of many organic compounds. Selenium is a trace element necessary for the proper functioning of enzymes, while sulfur is a key component of amino acids and proteins.

5. Industrial Applications:  Compounds of chalcogens have numerous industrial applications. For example, sulfuric acid \((H_2SO_4)\) is one of the most widely used industrial chemicals, with applications in fertilizer production, petroleum refining, and chemical synthesis. Tellurium is used in the production of solar panels and semiconductors.

Overall, the chalcogens exhibit diverse chemical behaviors and have significant implications in various fields, including chemistry, biology, and industry. Their position in Group 16 of the periodic table reflects their shared characteristics and chemical reactivities.