Ionization Enthalpy

What is Ionization Enthalpy?

Ionization Enthalpy means the Enthalpy which required to Remove a first electron from a Isolated Gaseous atom in its gaseous state. 

The energy required to remove a electron from isolated gaseous atom in its gaseous state is called as Ionization Enthalpy. It depends on Following factors:- 

1. penetration Effect 

The proximity of an electron in an orbital to the nucleus means the Penetration Effect. For each shell and subshell of electron, it observed as the relative density of electrons which is near the nucleus of an atom. 

The order of penetration power Trend is 2s > 2p > 3s > 3p > 4s > 3d

2. Force of attraction between nucleus and electrons. 

The Force of nucleus and electrons is also very important for Ionization Enthalpy. Means how much power is required to break the attraction between nucleus and electrons is the Ionization Enthalpy in simple words. 

As we move down the group atomic size increases so the distance between the outermost electron and nucleus also increases so less energy is required to break the attraction between nucleus and electron.