Question

Which element from following exhibits common oxidation state +2?

• A. Sr
• B. Rb
• C. Na
• D. Li

Hint:

Chemistry Tip: Group number for s-block elements corresponds directly to their most common oxidation state: Group 1 = +1; Group 2 = +2.

Answer 1

The Correct Option is A

Concept: Chemistry (Periodic Table) - Common Oxidation States of s-block Elements.

Step 1: Identify the group of the elements.
• Lithium (Li), Sodium (Na), and Rubidium (Rb): These are alkali metals belonging to Group 1 of the periodic table.
• Strontium (Sr): This is an alkaline earth metal belonging to Group 2.

Step 2: Analyze the valence electrons and common ions.
• Group 1 elements have one valence electron and typically lose it to achieve a noble gas configuration, resulting in a +1 oxidation state (e.g., $Li^+$, $Na^+$, $Rb^+$).
• Group 2 elements have two valence electrons. They achieve a stable noble gas configuration by losing both electrons, forming ions with a +2 oxidation state (e.g., $Sr^{2+}$).

Step 3: Conclude the correct element. Among the options, only Strontium (Sr) commonly exhibits the +2 oxidation state. $$ \therefore \text{The element that exhibits a common oxidation state of +2 is Sr.} $$