Electron gain enthalpy generally becomes more negative across a period as we move
from left to right. Within a group, electron gain enthalpy becomes less negative down
a group. However, adding an electron to the 2p-orbital leads to greater repulsion
than adding an electron to the larger 3p-orbital. Hence the element with most negative electron gain enthalpy is chlorine; the one with the least negative electron gain enthalpy is phosphorus.
Grade 12Inorganic Chemistry
what is -ve electron gain enthalpy??
