The reactivity series of metals is a ranked list that places metals in order of their decreasing chemical reactivity, from most reactive at the top to least reactive at the bottom. Reactivity is determined by a metal's tendency to lose electrons to form positive ions. Metals higher in the series, like potassium and sodium, are more reactive and readily lose electrons, while those lower, like copper and gold, are less reactive and more stable. This series predicts metal behavior in reactions, suc