Question

Which one of the following alkaline earth metals does not form hydride when it is heated with hydrogen directly?

• A. Be
• B. Mg
• C. Ca
• D. Sr

Hint:

Beryllium (Be) does not form hydrides directly because of its high ionization energy and its tendency to form covalent bonds rather than ionic bonds.

Answer 1

The Correct Option is A

Step 1: Understanding Hydride Formation Alkaline earth metals react with hydrogen to form hydrides. However, not all elements in this group readily form hydrides when heated with hydrogen.
Step 2: Analyzing Each Metal - Be (Beryllium): Beryllium does not form a simple hydride by direct reaction with hydrogen because it has a strong covalent character and does not easily bond with hydrogen. - Mg (Magnesium): Magnesium forms magnesium hydride (MgH₂) when heated with hydrogen. - Ca (Calcium): Calcium readily reacts with hydrogen to form calcium hydride (CaH₂). - Sr (Strontium): Strontium forms strontium hydride (SrH₂) when heated with hydrogen.
Step 3: Conclusion The correct answer is Beryllium (Be) because it does not form a hydride directly by heating with hydrogen.