is the amount of energy required to detach an electron from a singly charged negetive ion.
X- ------> X + é
Electron affinity is the energy released when an atom gains an electron to form a negative ion, while electron gain enthalpy is the enthalpy change accompanying the addition of an electron to a gaseous atom. Electron affinity is a specific term used in the context of forming an ion, while electron gain enthalpy is a general term for the enthalpy change associated with gaining an electron.
Electron Gain Enthalpy is the amount of Energy released when an isolated gaseous atom accepts an electron to become a monovalent gaseous anion.For Example:Atom(gas) +Electron ---->Anion(gas) +Energy(Electron Gain Enthalpy)
Group 8A, the noble gases because they have high electron affinity.
The enthalpy change for forming sodium chloride from its elements can be calculated using the equation: Enthalpy change = Ionization energy of sodium + Electron affinity of chlorine. Plugging in the values, we get: 496 kJ/mol + (-349 kJ/mol) = 147 kJ/mol. Therefore, the enthalpy change for forming sodium chloride is 147 kJ/mol.
Good question. Halogens have their outer electronic configuration as ns2np5 and require only one more electron to gain a stable electronic configuration. So they have a great affinity for electrons and will accept them very easily by releasing energy. So they have the highest electron gain enthalpy.
Inert gases are the most stable ones, so if we try to add another electron, the stable electronic configuration is disturbed. So, we have supply energy for this process. Hence, electron gain enthalpy is positive.
Ionization energy is the energy needed to remove an electron from an element, whereas electron affinity is the amount of attraction a substance has for a electron. One is the amount of energy to remove an electron while the other is the likeliness for it to attract an electron.
The electron gain enthalpies of Mg and P are almost zero because both elements are inherently stable in their neutral state (Mg+ and P-). They have a full valence shell configuration, which makes them reluctant to gain additional electrons and become more stable. This results in low electron affinity values for both elements.
on moving down the group the atomic size as well as nuclear charge inreases.But the effect of increase in atomic size is much more pronounced than that of nuclear charge and thus the additional electrons feels less attraction consequently electron gain enthalpy becomes less negative on going down the group
The electron gain enthalpy of hydrogen is approximately -72.8 kJ/mol, indicating that it releases energy when gaining an electron. In contrast, the electron gain enthalpy of phosphorus is approximately -78.6 kJ/mol, showing a larger energy release when phosphorus gains an electron due to its higher electronegativity.
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 higher electron gain enthalpy than Fluorine. The reason for this is that the size of Fluorine atom is very small and hence there is very high inter-electronic repulsion among the electrons of fluorine. This makes incoming of another electron not very favourable. Even though fluorine has large negative electron gain enthalpy but for chlorine its even more negative.
IONIZATION enthalpy is the amount of energy to lose electron from its outer most shell .