Which element is placed at the top of the electrochemical series?
Copper
Hydrogen
Sodium
Oxygen
Correct answer is C
In the electrochemical series, also known as the reactivity series, Sodium is placed at the top. The electrochemical series is a list of elements in the order of their standard electrode potentials (or redox potentials). Elements at the top of the series are more reactive and have a greater tendency to lose electrons and form positive ions.