Does a metallic element form an acid or base when it reacts with water?

Answer 1

Usually a metallic element will not react with water and so will not change pH.

However, a highly reactive metal, such as sodium, potassium or calcium will react with water to form the corresponding metal hydroxide, and so forms a base.

Answer 2

When you place a metallix element in water, the water becomes basic. The reason for this is that the electrons from the metal are removed and attach themselves a hydrogen of the H2O, this creates a positivly charged metal. A single hydrogen is released and pairs up with another hydrogen from another water molecule, thus creating H2, hydrogen gas. The hydroxide created by the release of 1 hydrogen bonds with the metallic substance. As there are more OH- in the solution, it becomes basic.