6 public questions tagged with this topic.
Electron gain enthalpy becomes more negative across a period and less negative down a group. In group 16, O (period 2) has the most negative value compared to S, Se, and Te.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electron Gain Enthalpy and Electronegativity and Valency
Electron affinity is the energy change for X + e⁻ -> X⁻. Cl has the highest electron affinity due to its balance of size and nuclear charge, though F’s electron gain enthalpy is less negative due to repulsion.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electron Gain Enthalpy and Electronegativity and Valency
Electron gain enthalpy becomes less negative down group 17 due to increasing size. Order: Cl (most negative) > F > Br.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electron Gain Enthalpy and Electronegativity and Valency
Electron gain enthalpy becomes less negative down group 17 due to increasing atomic size. Cl has the most negative value due to optimal nuclear charge and size, followed by F (less negative due to electron repulsion in its compact 2p orbitals), then Br. Order: Cl > F > Br.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electron Gain Enthalpy and Electronegativity and Valency
Electron gain enthalpy becomes more negative across a period and less negative down a group. Among O, S, F, and Cl, Cl (group 17, period 3) has the most negative value due to its high effective nuclear charge and smaller size than S.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electron Gain Enthalpy and Electronegativity and Valency
F has less negative electron gain enthalpy than Cl due to electron repulsion in its compact 2p orbitals, an anomaly in group 17 trends where Cl > Br > I.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electron Gain Enthalpy and Electronegativity and Valency
