A student observes that sodium's first ionization energy is lower than magnesium's. What atomic property explains this trend?
Q1. A student observes that sodium's first ionization energy is lower than magnesium's. What atomic property explains this trend?
Answer: Increased effective nuclear charge in Mg
Explanation: Mg's higher effective nuclear charge attracts electrons more strongly. Shielding (B) increases with atomic number but isn't decisive here.