Arrange the following elements in order of weakening of metallic properties: Ba, Be, Ca, Sr, Mg.

The metallic properties of chemical elements depend on the radius of the metal atom and on the number of electrons at the external electronic level. In our case, we are dealing with metals in the second group of Mendeleev’s Periodic Table of Chemical Elements. And therefore, at the external electronic valence level, they have two electrons. So these metals differ only in electron radii. So a number of these metals in order of weakening of their metallic properties are as follows.

Ba, Sr, Ca, Mg, Be.