Question

Which of the following does not belong to Group 16 elements?

• A. Oxygen
• B. Sulfur
• C. Selenium
• D. Chlorine

Hint:

Important group names in the periodic table:
• Group 1 \(\rightarrow\) Alkali metals
• Group 2 \(\rightarrow\) Alkaline earth metals
• Group 16 \(\rightarrow\) Chalcogens
• Group 17 \(\rightarrow\) Halogens
• Group 18 \(\rightarrow\) Noble gases Remember: \[ \text{O, S, Se, Te} \rightarrow \text{Group 16} \] \[ \text{F, Cl, Br, I} \rightarrow \text{Group 17} \]

Answer 1

The Correct Option is D

Concept: In the modern periodic table, elements are arranged into groups based on similarities in their electronic configuration and chemical properties. Group 16 elements are collectively known as the Chalcogens. These elements have six electrons in their outermost shell and generally show the valence shell electronic configuration: \[ ns^2 np^4 \] The common members of Group 16 are: \[ \text{O, S, Se, Te, Po} \]

Step 1: Identifying the position of each element in the periodic table.

• Oxygen (O) belongs to Group 16.
• Sulfur (S) belongs to Group 16.
• Selenium (Se) belongs to Group 16.
• Chlorine (Cl) belongs to Group 17.

Step 2: Understanding why chlorine is different.
Chlorine belongs to the Halogen family which is Group 17 of the periodic table. Its valence shell configuration is: \[ ns^2 np^5 \] Thus, chlorine contains seven valence electrons instead of six.

Step 3: Comparing the groups.
\[ \text{Group 16} \rightarrow ns^2 np^4 \] \[ \text{Group 17} \rightarrow ns^2 np^5 \] Therefore, chlorine does not belong to Group 16.

Step 4: Final conclusion.
Hence, the element which does not belong to Group 16 is: \[ \boxed{\text{Chlorine}} \] Therefore, the correct option is: \[ \boxed{(4)\ \text{Chlorine}} \]