How does the reactivity of the elements change as you go down the periodic table

The farther to the left and down the periodic chart you go, the easier it is for electrons to be given or taken away, resulting in higher reactivity

The metallic character increases as you go down a group. Since the ionization energy decreases going down a group, the increased ability for metals lower in a group to lose electrons makes them more reactive.

most community's take hundreds of years to become stable