4 public questions tagged with this topic.
For isoelectronic cations (Li+, Be²⁺, B³⁺, C⁴⁺, all with 2 electrons), radius decreases with increasing nuclear charge. B³⁺ (Z=5) is smaller than Li+ (Z=3), Be²⁺ (Z=4), and C⁴⁺ (Z=6).
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
Hydration enthalpy increases with smaller ionic size and higher charge density. Be²⁺ (smallest in group 2) has the highest hydration enthalpy compared to Mg²⁺, Ca²⁺, or Sr²⁺.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Genesis of Periodic Classification - Dobereiner Newlands Mendeleev
For isoelectronic species (N³⁻, O²⁻, F⁻, Na+, all with 10 electrons), radius increases with decreasing nuclear charge. N³⁻ (Z=7) has the largest radius.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electronic Configuration and Types of Elements - s p d f Blocks
For isoelectronic species (O²⁻, F⁻, Na+, Mg²⁺, all with 10 electrons), radius decreases with increasing nuclear charge. Mg²⁺ (Z=12) has the smallest radius.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electronic Configuration and Types of Elements - s p d f Blocks
