Question

What is the correct electronic configuration of alkaline earth metals?

Answer 1

Hint: For the electronic configuration of an alkaline earth metal, one must know which group they belong to. This will help you find the outermost electron shell configuration or the number of electrons. Elements in a group have the same no. of electrons in the outermost shell.

Complete answer:
We are all familiar with the periodic table. In a modern periodic table physical and chemical properties of the elements are periodic functions of their atomic numbers. In these periodic tables the horizontal rows or what Mendeleev called series are known as periods and the vertical column is called the group.
In a group elements have similar outermost electronic configurations in their atoms and are arranged in vertical columns. They are also called series. They are from group 1 to group 18. The elements in the group apart from the similar valence shell electronic configuration they also have similar properties.
Now coming to the question asked which is to state the electronic configuration of alkaline metals. The group 1 elements are called alkali metals whereas the Group 2 elements are called the alkaline earth metals. Group 2 electronic configuration is \[n{s^2}\]. These two groups belong to s-block elements. Their oxides remain in the crust of the earth and are very heat stable. They are highly reactive and therefore cannot be found pure in nature.

Note:
 To distinguish between the alkaline and alkali metals they have two and one electrons in their outermost shell. Alkali metals lose the outermost electrons and form \[{1^ + }\] ion whereas alkaline earth metals form \[{2^ + }\] ion.