electron affinity is the negative of electron gain enthalpy. for example, the electron gain enthalpy of fluorine is -328, and electron affinity is 328 which is -(-328)
electron gain enthalpy is the amount of energy released when an isolated gaseous atom accepts an electron to become a monovalent gaseous anion.
eq:atom(gas) +electron ---->anion(gas)...
Enthalpy is the energy of the molecules. It cannot be measured, although CHANGE in enthalpy of reactions can be measured. It's simply heat energy. Exothermic reactions have anegative enthalpy...
Even though Fluorine has the highest electronegativity among all the elements and it should have the highest electron gain enthalpy among all the halogens but this is an exception and chlorine has...