Using the general periodic table you developed in Question 25, show how the valence—electron configuration of most of the elements can be written just by knowing the relative location of the element on the table. Give specific examples.

Interpretation:

By using some examples, the valence electrons of some elements should be derived with the help of the location of element in the periodic table.

Concept Introduction:

Periodic table shows the arrangement of elements in order of increasing atomic number. The horizontal rows are periods and vertical rows, or columns are groups. The elements are represented by symbols with atomic number and atomic mass. The element is in its most stable state as it is represented in the periodic table. The group number helps in identifying the valance electrons and some properties of the element.

There are four blocks in which elements are categorized in the periodic table and they help in writing electron configuration of most of the elements.

Electron configuration describes the arrangement of electrons within the orbitals and sub orbitals of an atom. Valence-electron configuration is how electrons are arranged in the outermost shell.

Valence electron configuration of Oxygen = 2s² 2p⁴

The atomic number of Oxygen is 8 and it is located in period 2 and group 6A of the periodic table. In the case of Oxygen the electron configuration of the valence shell is written. Oxygen is in the p block, so Oxygen should have filled s suborbital and incomplete p suborbital in its valence shell. Since, Oxygen is in group 6A, it should have 6 valence electrons. For second period, the main orbital number is 2. So, the valence electronic configuration of oxygen becomes 2s² 2p⁴.

Valence electron configuration of Sodium = 3s¹

The atomic number of sodium is 11 and it is located in period 3 and group 1A of the periodic table. Sodium is in the s block so, sodium should have only incomplete s suborbital in its valence shell