Latest questions in this category.
Third ionization enthalpy peaks when removing an electron from a noble gas-like X²⁺ ion. Ca (after losing two electrons, becomes Ca²⁺ with 1s² 2s² 2p⁶ 3s² 3p⁶) 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
Metalloids lie along the metal-non-metal boundary. Si (group 14) is a metalloid, while Na (group 1), Mg (group 2), and S (group 16) are not.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
Atomic radius increases down a group due to additional electron shells. For group 2: Be < Mg < Ca.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
Fourth ionization enthalpy peaks when removing an electron from a stable X³⁺ ion. Si (after losing three electrons, becomes Si³⁺ with 1s² 2s² 2p⁶) 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 peaks when removing an electron from a noble gas-like X²⁺ ion. Sr (after losing two electrons, becomes Sr²⁺ with 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶) has the highest value in period 5.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
First ionization enthalpy increases across a period. Among Na, Mg, Si, and Ar, Ar (group 18, period 3) has the highest value due to its stable noble gas configuration.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
Fourth ionization enthalpy is highest for C (removing an electron from C³⁺ with 1s²) due to its small size and stable configuration, compared to Si, Ge, or Sn.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
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
Bond angles in group 15 hydrides (NH₃, PH₃, AsH₃, SbH₃) decrease down the group due to reduced hybridization. NH₃ (107°) has the highest bond angle.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
Fifth ionization enthalpy peaks when removing an electron from a stable X⁴⁺ ion. P (after losing four electrons, becomes P⁴⁺ with 1s² 2s² 2p⁶) has the highest value in period 4.
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 when removing an electron from a noble gas-like configuration. Mg (after losing two electrons, becomes Mg²⁺ with 1s² 2s² 2p⁶) 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
Bond strength in group 14 monoxides (XO) decreases down the group due to weaker orbital overlap. CO (triple bond) has the highest bond strength compared to SiO, GeO, or SnO.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy
