The decrease in radius is large for divalent cations but larger for trivalent cations because of:

Explanation

Successive loss of electrons refers to the process of an atom losing multiple electrons in a stepwise manner to form cations with progressively higher positive charges. When an atom loses one electron, it forms a monovalent cation with a charge of +1. If the atom continues to lose electrons, it can form divalent cations with a charge of +2, trivalent cations with a charge of +3, and so on. Successive loss of electrons occurs as electrons are removed from the outermost energy levels (valence electrons) of an atom. The removal of each electron reduces the number of negatively charged electrons and increases the effective nuclear charge experienced by the remaining electrons. As a result, the attraction between the positively charged nucleus and the remaining electrons becomes stronger. The successive loss of electrons leads to a decrease in the atomic radius as the electron cloud becomes more strongly pulled towards the nucleus. Additionally, as more electrons are removed, the ionization energy required to remove each subsequent electron generally increases. Overall, successive loss of electrons results in the formation of cations with higher positive charges and smaller atomic radii.