Why Sodium And Potassium Really Explode In Water Inorganic Chemistry: High-speed photography and modeling reveal that classic reaction gets its oomph from sudden repulsion between alkali ions ...

This explains the continued robust reaction: the spikes kept placing fresh sodium in contact with the water, preventing the formation of a steam/hydrogen barrier that would choke off the reaction.

The spectacular reaction of alkali metals with water was poorly understood — despite being a staple of chemistry classes. It’s the classic piece of chemical tomfoolery: take a lump of sodium ...

Alkali metals can react explosively with water and it is textbook knowledge that this vigorous behaviour results from heat release, steam formation and ignition of the hydrogen gas that is produced.