Recall the order of potassium, sodium, lithium, calcium, magnesium, carbon, zinc, iron, hydrogen, copper and gold in the reactivity series.

The reactivity series is a list that ranks metals based on their reactivity, from most reactive to least reactive. In this series, potassium is the most reactive, followed by sodium, lithium, calcium, magnesium, carbon, zinc, iron, hydrogen, copper, and finally gold, which is the least reactive. Understanding this order helps predict how metals will react with water, acids, and other substances. For example, more reactive metals can displace less reactive metals from their compounds, which is crucial in applications such as extraction and metal displacement reactions.