The electronic configuration of the outer 3s2 3p1 electron layer corresponds to an atom.

In the periodic table of the chemical elements of Mendeleev, the elements are arranged in such a way that the number of the period corresponds to the number of electronic layers of the element. And the number of electrons on the outer layer is equal to the group number.

The designation for the outer electron layer looks like 3s2; 3p1, which means this is the third electron layer from the nucleus. That. the element is located in the third period.

In total, there are three electrons on the outer electron layer, which means it will be an element from the third group.

We are looking for the intersection of the third group and the third period. The cell found contains the element aluminum – Al.