Ionisation potential does not depend upon:

a. Atomic size:
The ionization potential is defined as the amount of energy required to remove an electron from an atom or ion in its gaseous state. It is influenced by various factors, but atomic size is not one of them. Atomic size refers to the distance between the nucleus and the outermost shell of electrons. While larger atoms generally have higher ionization energies due to increased electron-nucleus attraction, atomic size alone does not determine the ionization potential. Other factors such as electron configuration and shielding effects play a more significant role.

b. Type of electron:
The ionization potential is not dependent on the type of electron. Whether it is a valence electron or an inner electron, the energy required to remove it remains the same. The ionization potential is determined by the effective nuclear charge experienced by the electron and the electron's distance from the nucleus.

c. Nuclear charge:
The ionization potential is influenced by the nuclear charge or the number of protons in the nucleus. As the nuclear charge increases, the attraction between the nucleus and the electrons strengthens, resulting in a higher ionization potential. This is because the electrons are held more tightly and require more energy to be removed. However, it is important to note that nuclear charge alone does not determine the ionization potential; other factors such as electron shielding and orbital stability also play a role.

d. Type of bonding in crystal lattice:
The type of bonding in a crystal lattice, such as ionic, covalent, metallic, or molecular, does not directly affect the ionization potential. The ionization potential is primarily determined by the electronic structure of the atom or ion being considered. The bonding in a crystal lattice affects the overall stability and arrangement of atoms, but it does not directly influence the energy required to remove an electron from an individual atom or ion.

In conclusion, the ionization potential is not dependent on atomic size, the type of electron, the type of bonding in a crystal lattice, or the nuclear charge alone. It is influenced by a combination of factors including electron configuration, shielding effects, and the effective nuclear charge experienced by the electron.

D. Type of bonding in crystal lattice