Which metal is more reactive? Sodium or Copper?

Sodium is more reactive than copper due to its position in the reactivity series of metals, which ranks metals according to their ability to displace other metals from compounds and their reactivity with water and acids. Sodium, being an alkali metal, has a single electron in its outer shell, allowing it to lose that electron easily and participate in chemical reactions. This characteristic makes sodium highly reactive, particularly with water, where it can produce hydrogen gas and sodium hydroxide.

Copper, on the other hand, is a transition metal with a more stable electronic structure and does not readily lose its outer electrons compared to sodium. As a result, it is much less reactive than sodium and does not react with water or dilute acids in a significant way. This further emphasizes why sodium is the more reactive metal in comparison to copper.