Displacement Reactions
Displacement Reactions is when a stronger metal pushes a weaker metal out of a solution, trading places with it.
Think of it this way
Drop an iron nail into a cup of blue copper sulfate water. After a day, the nail has an orange copper coating and the blue water has faded. The iron shoved the copper out of the liquid and took its place. The stronger metal pushed the weaker one aside, like a bigger kid claiming a seat on the bench.
Explaining displacement reactions by grade level
Imagine dropping a piece of iron into blue water that has copper mixed in. The iron is stronger, so it shoves the copper out. Slowly the copper sticks to the iron as an orange coating, and the blue water fades. The strong metal took the weak metal's spot.