Explain why the first ionization energy of aluminum (atomic number 13) is lower than…

CHEMISTRY · Subjective · A Level · Chemistry · Periodicity and periodic trends · Periodicity and periodic trends

Problem

Explain why the first ionization energy of aluminum (atomic number 13) is lower than that of magnesium (atomic number 12), even though aluminum has a greater nuclear charge. Your response should mention electron configuration and shielding effects.

Related theory

Electronic Configuration
Atomic Structure
Ionisation potential
Ionisation enthalpy
Classification of Elements and Periodicity in Properties
Periodic Trends in Physical Properties

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