As we go down in the electro-chemical series of metals, the reactivity ______.

The higher the metal in the series, the more reactive it is and the more vigorously it reacts with water, oxygen and acid.  Metal in the activity series can displace any metal below it in the series from its compound. The elements potassium, sodium, lithium and calcium are very reactive and they react with cold water to produce hydroxides and hydrogen gas. . The metals above hydrogen are more reactive than hydrogen. These metals can displace hydrogen from acids or water and liberate hydrogen gas. The metals copper, silver gold and platinum are less reactive than hydrogen and they do not replace hydrogen from water or acid.

Hence, As we go down in the electro-chemical series of metals, the reactivity decreases.