Question #20bda

1 Answer
Apr 16, 2017

In theory it would be francium.

Explanation:

Francium is the last alkali metal (group I/IA). The alkali metals are extremely reactive and the reactivity increases down the group. However, Francium is radioactive and has a very short half-life (22 minutes for the longest half-life), and it is very rare. So scientists are unable to verify the theoretical physical and chemical properties of francium.