9 public questions tagged with this topic.
First ionization enthalpy decreases down a group. Among B, Al, Ga, and Tl (group 13), B (period 2) has the highest value.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
Third ionization enthalpy is highest for B (removing an electron from B²⁺ with 1s²) due to its small size and stable configuration, compared to Al, Ga, or In.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
Third ionization enthalpy decreases down group 13 as size increases, reducing nuclear attraction. Tl (period 6) has the lowest value among B, Al, Ga, and Tl.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
Acidity of group 13 trioxides decreases down the group. B₂O₃ (B, smallest) is the most acidic, forming boric acid, unlike Al₂O₃ (amphoteric), Ga₂O₃, or In₂O₃.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Nomenclature of Elements with Atomic Number >100
B forms B₂H₆, an electron-deficient hydride with three-center two-electron bonds, unlike Al (AlH₃, polymeric), Ga, or In, which form less distinct hydrides.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Genesis of Periodic Classification - Dobereiner Newlands Mendeleev
B₂O₃ (covalent, network structure) is highly resistant to hydrolysis, unlike Al₂O₃ (amphoteric), Ga₂O₃, or In₂O₃, which react more readily with water or acids/bases.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electron Gain Enthalpy and Electronegativity and Valency
B (group 13) has a covalent network structure, giving it an exceptionally high melting point compared to Al, Ga, or In, which are metallic.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Anomalous Properties and Second Period and Chemical Reactivity
Polarizing power increases with smaller size and higher charge density. B³⁺ (smallest in group 13) has the highest tendency to form covalent compounds (e.g., BF₃) compared to Al, Ga, or In.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Anomalous Properties and Second Period and Chemical Reactivity
Metallic character increases down group 13. B (period 2) is a metalloid with minimal metallic properties, unlike Al, Ga, or In, which are more metallic.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Anomalous Properties and Second Period and Chemical Reactivity
