Question

Name one metal which fit each of the following
A metal which floats on water, reacts with it and forms an alkali.

Answer 1

The elements which floats on water belongs to I group such as lithium, sodium, and potassium

Lithium is the lightest metal and gas density about half of water. It reacts quite vigorously with water and releases a large amount of hydrogen.

This case is same for sodium and potassium , so they both float in water