By Karl and Fedora Reactivty series of metals? The reactivity series of metals is a chart listing metals in order of decreasing reactivity. In general, the more reactive a metal is: the more vigorously(powerfully) it reacts with other substances and the more easily it loses electrons to form positive ions (cations) The reactivity series Facts An inert chemical substance is one that is not generally reactive. This is a synonym for "inactive" with respect to chemical reactions. I The most reactive metal is pottasium which needs to be kept in oil so that it doesnt react The least reactive metal is platinum.Although, it is genrally not addded in our memorising chart Most of these elemnts are stored in oil to avoid it from reacting with water and oxygen