Can alkali metals float on water?

Alkali metals, such as lithium, sodium, and potassium, are less dense than water, allowing them to float. However, when they come into contact with water, they react vigorously, producing hydrogen gas and heat, which can ignite the hydrogen. This reaction can be quite explosive, especially with heavier alkali metals like sodium and potassium. Therefore, while they can float, the reaction poses significant safety risks.