Electron gain enthalpy with negative sign of fluorine is less than

Chlorine has the highest value of electron gain enthalpy

Ionization enthalpy is the energy required to remove an electron from an isolated gaseous atom in its ground state. Although the atoms are widely separated in the gaseous state, there...

[Hint : Due to smaller size of oxygen than sulphur electron-electron repulsion is more in oxygen than sulphur.]

[Hint : Due to small size of F atom and compact 2p orbitals there are strong interelectronic repulsions in the relatively smaller 2p orbitals of fluorine. So the incoming electron...

[Hint : Due to its low bond dissociation enthalpy (F-F bond) and high hydration enthalpy of F-.]

(c) Assertion is correct, reason is incorrect 

(i) This is due to smaller size of oxygen the electron cloud is distributed over a small region of space, making electron density high which repels the incoming electrons. (ii) Because...

Second electron affinity of O is largely +ve because of repulsion between negatively charged ions and second electron to be added. Energy required to overcome repulsion is more than the...

The electron gain enthalpy for halogens is highly negative because they can acquire the nearest stable noble gas configuration by accepting an extra electron. 

(d) electron gain enthalpy becomes more negative as we go down a group.