Why does aluminum have a lower first ionization energy than magnesium despite coming later in the periodic table?
Q1. Why does aluminum have a lower first ionization energy than magnesium despite coming later in the periodic table?
Answer: Electron configuration with a new p-orbital
Explanation: Aluminum's 3p orbital is less stable than magnesium's filled 3s, lowering its IE. Radius and metallic character are unrelated.