Which one of the elements has the maximum electron affinity ?
Which one of the elements has the maximum electron affinity ?
The correct option is B Cl
Lets recall something,
Atomic size: In general electron gain enthalpy value becomes less negative with he increasing atomic radius because electrostatic force of attraction decreases between the electron being added and the atomic nucleus due to increase of distance between them.
Electron gain enthalpy α1Atomic Size
Effective Nuclear Charge: Electron gain enthalpy value of the element becomes more negative as the effective nuclear charge on the atomic nucleus increases because electrostatic force of attraction between the electron being added and the nucleus increases. As the electrostatic force of attraction increases, amount of energy released is more.
Electron gain enthalpy α Effective nuclear charge
Electron Affinity (Ac) term can also be used to measure ability of an atom to gain electron. If energy is released when an electron is added to an atom, the electron affinity is taken as positive, contrary to thermodynamic convention.
Then because
I > Br > Cl > F [Atomic Radius]
⇒ It should be
F > Cl > Br > I [EA]
But
As we know,
Atomic size: In general electron gain enthalpy value becomes less negative with he increasing atomic radius because electrostatic force of attraction decreases between the electron being added and the atomic nucleus due to increase of distance between them.
Electron gain enthalpy
Electron gain enthalpy α1Atomic Size
Therefore, F > Cl [Electron Gain Enthalpy]
But, Florine is very small, therefore electron density is high and an increased electronic repulsion makes addition of an electron to fluorine less favorable than that in case of Chlorine.
Therefore, the order will be
Cl> F > Br> I [EA]
⇒ Cl has maximum electron affinity.
Cl
Lets recall something,
Atomic size: In general electron gain enthalpy value becomes less negative with he increasing atomic radius because electrostatic force of attraction decreases between the electron being added and the atomic nucleus due to increase of distance between them.
Electron gain enthalpy α1Atomic Size
Effective Nuclear Charge: Electron gain enthalpy value of the element becomes more negative as the effective nuclear charge on the atomic nucleus increases because electrostatic force of attraction between the electron being added and the nucleus increases. As the electrostatic force of attraction increases, amount of energy released is more.
Electron gain enthalpy α Effective nuclear charge
Electron Affinity (Ac) term can also be used to measure ability of an atom to gain electron. If energy is released when an electron is added to an atom, the electron affinity is taken as positive, contrary to thermodynamic convention.
Then because
I > Br > Cl > F [Atomic Radius]
⇒ It should be
F > Cl > Br > I [EA]
But
As we know,
Atomic size: In general electron gain enthalpy value becomes less negative with he increasing atomic radius because electrostatic force of attraction decreases between the electron being added and the atomic nucleus due to increase of distance between them.
Electron gain enthalpy
Electron gain enthalpy α1Atomic Size
Therefore, F > Cl [Electron Gain Enthalpy]
But, Florine is very small, therefore electron density is high and an increased electronic repulsion makes addition of an electron to fluorine less favorable than that in case of Chlorine.
Therefore, the order will be
Cl> F > Br> I [EA]
⇒ Cl has maximum electron affinity.
