Question

Which of the following is the correct order with respect to the property indicated?

• A. Cl>F (Ionisation energy)
• B. K₂O>Na₂O>Al₂O₃ (Basic nature)
• C. K>Na>Mg>Al (Metallic character)
• D. None of these

Hint:

In periodic trends, ionisation energy increases across a period and decreases down a group, while metallic character behaves oppositely.

Answer 1

The Correct Option is B

Step 1: Understanding the properties.
- Ionisation energy: F has the highest ionisation energy because of its small size, followed by Cl.
- Basic nature: As we move down the group, the basic nature increases due to the increasing ionic size and decreasing bond strength. Thus, K₂O>Na₂O>Al₂O₃ is the correct order for basic nature.
- Metallic character: The metallic character decreases from left to right across the period and increases from top to bottom. Therefore, K>Na>Mg>Al is the correct order for metallic character.
Step 2: Conclusion.
The correct answer is (2) K₂O>Na₂O>Al₂O₃ (Basic nature) as per the analysis above.