Answer to Question #238453 in General Chemistry for Sachi

Question

Explain why the first ionization energy of Aluminum (Al) is less than that of Magnesium

(Mg)

Answer 1

So the extra amount of protons means the nucleus holds the outer electrons more strongly so it requires more energy to remove an electron. Aluminium has a lower ionisation energy than Magnesium. This is unexpected as Al has more protons. This can be explained by electron configurations.