Chemistry · Periodic trends in properties of elements: atomic and ionic radii, ionization enthalpy, electron gain enthalpy, valence, oxidation states and chemical reactivity
Which has the smallest size?
Which has the smallest size?
- A. \( N a^{+} \)
- B. \( M g^{2+} \)
- C. \( A l^{3} \)
- D. \( P^{5} \)
Step-by-step solution
All ions are isoelectronic with Ne (10 electrons). Ionic size decreases with increasing nuclear charge: Na⁺ (Z=11), Mg²⁺ (Z=12), Al³⁺ (Z=13), P⁵⁺ (Z=15). The highest nuclear charge gives the smallest radius.