In order to determine the incorrect statement about ionization enthalpy, we need to understand the concept of ionization enthalpy and evaluate each given option:
- Ionization enthalpy increases for each successive electron. This statement is correct. As electrons are removed from an atom, the ion becomes more positively charged, increasing the force of attraction between the remaining electrons and the nucleus. Therefore, more energy is required to remove each successive electron, leading to higher ionization enthalpy.
- The greatest increase in ionization enthalpy is experienced on removal of an electron from core noble gas configuration. This statement is correct. Electrons in a complete shell close to the nucleus, especially those with a noble gas configuration, require significantly more energy to remove due to the stable configuration and strong effective nuclear charge.
- End of valence electrons is marked by a big jump in ionization enthalpy. This statement is correct. When all valence electrons have been removed, removing the next electron involves breaking into the inner electronic shell which is much closer to the nucleus, therefore requiring much more energy, causing a substantial increase in ionization enthalpy.
- Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value. This statement is incorrect. Electrons in orbitals with lower principal quantum number \( n \) are closer to the nucleus and are more tightly held due to stronger electrostatic forces. Therefore, removing electrons from lower \( n \) orbitals is more difficult and requires more energy compared to higher \( n \) orbitals, which are farther from the nucleus.
Thus, the incorrect statement is: Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.