7 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
For isoelectronic species (10 electrons), ionic radius decreases with increasing nuclear charge. Al³⁺ (Z=13) has the lowest radius compared to Na+, Mg²⁺, or F⁻.
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 (10 electrons), radius decreases with increasing nuclear charge: Mg²⁺ (Z=12) < Na+ (Z=11) < F⁻ (Z=9).
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Genesis of Periodic Classification - Dobereiner Newlands Mendeleev
Ionic radius increases down group 17. Among F⁻, Cl⁻, Br⁻, and I⁻, I⁻ (from I, period 5) has the largest radius.
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
For isoelectronic species (36 electrons), radius increases with decreasing nuclear charge. Br⁻ (Z=35) has the largest radius compared to K+, Ca²⁺, or Sc³⁺.
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
