Question

A metal X can replace a metal Y from its salt solution. But Y cannot replace X from its salt solution. Which metal is higher up in the reactivity series?

Answer 1

Metal X replaces metal Y but metal Y is not able to replace metal X, this means that metal X is higer up in the reactivity series. A metal which is higher up in the reactivity series can replace another metal which is placed below in the reactivity series but the opposite of this is not possible.