Question

Alkali metals ions should decrease in the order lithium sodium potassium rubidium cesium but actually the trend is just reverse why?

Answer 1

But the alkali metals cannot form ions as the magnitude of second ionization energy is very high. ... However lithium is the strongest reducing agent. .... sodium forms peroxide, Na2O2, whereas potassium rubidium and caesium form ... The order of reactivity of the alkali metals towards hydrogen decreases as we move down ...