Four successive members of the first row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionization energy ?

To determine which element will have the highest third ionization energy, we need to analyze the electronic configuration of each element. So, let's consider each option: option 1 involves Vanadium, option 2 involves Chromium, option 3 involves Iron, and option 4 involves Manganese. Notice that the third ionization energy involves the removal of a third electron from the atom, which requires more energy if the electron is removed from a stable half-filled or completely filled subshell. Think of it this way: the third ionization energy is higher for elements with stable half-filled or completely filled subshells, because the removal of an electron from these subshells requires more energy. In other words, the third ionization energy is higher for elements with stable electronic configurations. Therefore, the correct answer is the option that involves an element with a stable electronic configuration, which is option 4.