How can a Metal reacting with Water/Steam show how Reactive it is? -What happens if Potassium, Zinc and Copper react with Water/Steam

-The more Violent the Reaction is, the more Reactive it is -Potassium will react Violently with the Water, making it a Reactive Metal, which it is -Zinc won't really do much with Water, but with Steam it can play around more [It can React with Steam] -Copper literally will do Nothing. Easy