Activity Series

Imagine you're at a party trying to form a dance circle, but some people are more eager to join in and show off their moves than others. This situation is similar to the activity series in chemistry, where elements are ranked based on their eagerness, or activity, to engage in chemical reactions. Just as the most enthusiastic dancers jump into the circle first, in the activity series, elements like potassium and sodium are more "excited" to react and therefore appear at the top of the list, while less reactive elements like gold and platinum hang back, waiting their turn.
Practice Version

Activity Series: A list of elements arranged by descending order of chemical activity. Activity series. The activity series is a ranking of elements from most to least reactive, used to predict how they will behave in chemical reactions.