Get your free Ultimate Chemistry Cheat Sheet here: https://www.chemin10.com/optin?ims=jemvs&utm_source=YT+Periodic+Table Isoelectronic Series Atomic Radius An isoelectronic series is a series of elements and ions that have equal numbers of electrons. Since they each have the same number of electrons, their periodic trend in atomic radius and ionic radius predicts that the isoelectronic species with the greatest number of protons will have the smallest radius. This is because, according to Coulomb's law, the larger nuclear charge of the species with the greatest number of protons results in an increase in the attraction between between the nucleus and its outermost electrons. This increase in the attractive force brings the outermost electrons in closer to the nucleus, resulting in a smaller radius. Today's chemistry question of the day: Which of the following has the largest radius? A. Sr2+ B. Rb+ C. Kr D. Br- E. Se2- Join us at http://chemin10.com to receive the Chemistry Question of the Day delivered to your inbox, as well as more videos and an online chemistry community of like-minded chemistry students! https://youtu.be/QOKVAAc2MN8 isoelectronic series isoelectronic species isoelectronic species radius isoelectronic species atomic radius isoelectronic species ionic radius isoelectronic series size isoelectronic series atomic radius