What is the valency of the alkali metals?

Alkali metals are found in group 1 of the periodic table. They all have an oxidation (valence) number of +1 which means when they bond with other atoms they give up 1 electron, which makes them cations. (This is opposed to the halogens in group 17 of the periodic table which all have an oxidation number (valence) of -1 which means they accept electrons when bonding with other atoms and are called anions) All of the elements in group 1 react violently with water and the hydrogen gas can ignite.