1. Tardigrade
  2. Question
  3. Chemistry
  4. Which represents the correct order of first ionisation potential of third period elements?

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. Which represents the correct order of first ionisation potential of third period elements?

AFMCAFMC 2009Classification of Elements and Periodicity in Properties

Solution:

Generally, ionisation potential increases, as we move from left to right in a period. However, the ionisation potential of II group elements is higher than that of the III group elements. This is because of the fully filled $s$-orbitals in II group elements.
Hence, the correct order of ionisation potential is
$Na < Al < Mg < Si$