Question

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

• A. \( \mathrm{Cl>F} \) (Ionisation energy)
• B. \( \mathrm{K_2O>Na_2O>Al_2O_3} \) (Basic nature)
• C. \( \mathrm{K>Na>Al>Mg} \) (Metallic character)
• D. None of these

Hint:

Periodic trends to remember: \begin{itemize} \item Ionisation energy increases across a period, decreases down a group \item Metallic character decreases across a period \item Basic nature of oxides decreases from left to right \end{itemize}

Answer 1

The Correct Option is B

Option (A): Incorrect. Ionisation energy decreases down a group, hence: \[ \mathrm{F>Cl} \] Option (B): Correct. Basic nature of metal oxides decreases from left to right across a period: \[ \mathrm{K_2O>Na_2O>Al_2O_3} \] Option (C): Incorrect. Metallic character decreases across a period. Correct order is: \[ \mathrm{K>Na>Mg>Al} \] Option (D): Incorrect since option (B) is correct.