Define ionisation enthalpy. how does it vary along the group and along the period?
Answers
Answer:
ionisation energy is qualitatively defined as the minimum amount of energy required to remove the loosely held electron, the valence electron of an isolated gaseous atom to form a cation
As move from left to right ionisation energy increase gradually.
As we go down the group ionisation energy decreases gradually
Answer:
Ionization enthalpy is the energy required to remove the most loosely bound electron from an isolated gaseous atom.
The size decreases as we move from left to right in a period because the valence shell come closer to the nucleus as we move from left to right. Thus, the removal of electron from the valence shell becomes difficult due to greater attraction between nucleus and valence electron. Thus, the ionization enthalpy increases from left to right in a period.
The size increases as we move from top to bottom in a group. As, the electrons get added up in the new shell, the electron in the outermost orbital gets far away from the nucleus. And hence, the electron will be easier to remove. Thus, the ionization enthalpy decreases from top to bottom in a group.