For an isoelectronic series of ions, the ion that is the smallest is always 1. the ion with the most electrons. 2. the ion with the fewest protons.

Respuesta :

Answer:

the ion with the most electrons

Explanation:

Ionic size generally depends on weather the ions are negative or positive. Averagely, atoms become smaller on moving from left to right in the periodic table. A movement from left to right in the periodic table leads to a gradual increase in the number of electrons and decrease in atomic size. Li+, Be2+ and B3+ are all isoelectronic but B3+ is the smallest ion.