Magnesium burns well underwater. Anything will burn underwater if it has a proper amount of oxidizing material.
alumin
Sodium is a metal that burns readily underwater. When exposed to water, sodium reacts vigorously, releasing hydrogen gas and generating enough heat to ignite the hydrogen, resulting in a bright yellow flame.
To walk underwater, you need metal wario.
Aluminum
Metals that react well with water: Sodium - fizzes Potassium - burns Caesium - explodes Metals that react well with acids: Magnesium
Magnesium
oxide.
He turns to metal when he is metal he can walk underwater and is invicible for a limeted time.
Metal can quickly rust when it is exposed to water and oxygen, which causes a chemical reaction that forms rust on the surface of the metal.
One can purchase an underwater metal detector at a local all round hobby store or at a metal detector store. One can also buy one on various webshops like Amazon or eBay.
magnesium
Magneseum. an Alkali earth metal