Which of the following atom or ions has the smallest size? — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

Step 1: Compare neutral atoms across a period (N, O, F). Atomic radius decreases from left to right as effective nuclear charge increases, making F the smallest neutral atom among them. Step 2: Compare a neutral atom to its anion (F vs F^-). An anion is always larger than its parent atom due to increased electron-electron repulsion and a lower effective nuclear charge per electron. Step 3: Therefore, neutral Fluorine (F) has the smallest size among all the options.