Question #898a6

Alkaline earth metals are located in group 2 of the periodic table, which implies that they each have 2 electrons in their outermost shells.

![http://www.askiitians.com/iit-jee-s-and-p-block-elements/alkaline-earth-metals/]()

The electrons located in the outermost shell of an atom are called valence electrons.

Alkaline earth metals will readily react to give up those two electrons in order to gain a complete octet, which is characterized by the presence of 8 electrons in the outermost shell.

Berylium is an exception to this; since it doesn't have enough electrons to be able to obtain a complete octet, berylium will lose those two valence electrons in order to form a stable duet configuration.

The electron configutations of the group 2 elements reveals the two valence electrons each of those atoms have.

![http://www.online-sciences.com/the-matter/the-properties-of-the-alkaline-earth-metals-group-2-a/]()

As you can see, in order to form a complete octet (or duet as mentioned earlier), every one of these atoms will give up the two electrons located in their outermost shells to form 2+ cations.

The valency of the alkaline earth metals is thus said to be 2, meaning that they each have two valence electrons.