Which element is more reactive Na or Fr?

Na has electronic structure 2.8.1

Fr has electronic structure 2.8.18.32.18.8.1

Na has one electron in 3rd shell, while Fr has it in the 7th shell.

My guess would be that since 7th shell is further away from nucleus than the 3rd shell, Fr would be more reactive.

This is the kind of question that needs an illustration. Watch the video below. At the beginning you see a small amount of lithium, sodium and potassium raction in water, then you see a small amount of rubidium and cesium reacting in water.

Francium isn't legal in the UK (where this clip was made), for good reason. If you look on your periodic table and compare the severity of the reaction of the previous five metals with their position on the periodic table, you should see a pattern.

And where's Francium? It's the next element in that pattern... So do you think it's very reactive? :D

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