What is common feature in the electronic configuration of metal atoms
Metals are the elements which loose their valence electrons and forms a positive charged ion called cation.
Take the examples of metals, Sodium (), Calcium () and Aluminium ().
The electronic configuration of Sodium () is
The electronic configuration of Calcium () is
The electronic configuration of Sodium () is
In the above examples we can see that metals are going to have 1, 2 or 3 electrons in their valence shell.
Therefore, the common feature in the electronic configuration of metal atoms is that they are going to have 1, 2 or 3 electrons in their valence shell and they can be donated easily.