Question

How do electronic configuration correspond to the periodic table?

Answer 1

Hint: If one knows the electronic configuration and filling of orbitals in each atom, we can easily assign the group number of those atoms in the periodic table.

Complete step by step answer:
We know that electronic configuration is the arrangement of electrons in the different orbitals in an atom following the Aufbau rule. The Aufbau principle states that the electrons are first filled into the lower energy orbitals and then in higher energy orbitals in the ground state of that atom. This is done to attain a stable electronic configuration of the element.
In the periodic table, the period represents the principal energy level and the group represents to what extent the orbitals are filled. As there is a change in the filling of electrons in the orbitals there is a change in the physical or chemical properties of the elements. The electrons in the valence shell are very important because they directly participate in the chemical reaction process.
The elements in group 1 will have only one electron in its valence shell in s orbital. Similarly, the second group of the periodic table will have an outermost s orbital filled with two electrons of different spins. The groups of boron family, carbon family, nitrogen family, oxygen family and halogens are the groups concerned with the filling of the p orbital. So, members of group 3 will have three valence electrons; two in s orbital and one in the p orbital.
Similarly, members of group 4 will have four valence electrons; two in s orbital and two in the p orbital.
Members of group 5 will have five valence electrons; two in s orbital and three in the p orbital.
Members of group 6 will have six valence electrons; two in s orbital and four in the p orbital.
Members of group 7 will have seven valence electrons; two in s orbital and five in the p orbital.
Members of the noble gas group, group 0 will have its octet complete with two electrons in the s orbital and six electrons in the p orbital.
For the transition metals, groups 3-12, there are many exceptions. The general rule is that the element's electron configuration ends in d and whatever place they are in. similarly the rare earth metal i.e., the f block elements have their electronic configuration ending with f.

Note: Each new element of the periodic table adds a valence electron. A new period of the Periodic table starts with the s electron and ends with 6 P electrons. The (n - 1)d electrons are added before the n P electrons and the (n - 1)f electrons are added before n d electrons.