Question

Why beryllium is not included in Alkali earth metals?

Answer 1

Alkaline metals are called so because of two reasons:

i) They are obtained from the earth in the form of ores.

ii) Their oxides and hydroxides show basic (alkaline) natures.

Beryllium fulfills the first criterion but not the second one, since its oxides and hydroxides show amphoteric behavior, rather than alkaline. So, it is not considered an alkaline earth metal.

Answer 2

Alkaline earth metals are metals which belong to group 2 in the period ic table and are commonly found in the Earth's ore and the aqueous solutions of these metals oxides/hydroxides need to be alkaline (as the name suggests).

Beryllium oxide/hydroxides are amphoteric. Hence it is not an alkaline earth metal.