When two elements are located on opposite sides of the periodic table, they are likely to form an ionic bond. This is because one element is usually a metal that has a tendency to lose electrons, while the other is a nonmetal that tends to gain electrons.
For example, consider sodium (Na), which is a metal found on the left side of the periodic table, and chlorine (Cl), which is a nonmetal located on the right side. Sodium has one electron in its outer shell that it can easily lose, forming a positively charged ion (Na+). On the other hand, chlorine has seven electrons in its outer shell and needs one more to achieve a full octet, so it gains the electron from sodium, forming a negatively charged ion (Cl–).
This transfer of electrons results in the formation of ionic compounds, which are characterized by the strong electrostatic attraction between the oppositely charged ions. Therefore, when elements from opposite ends of the periodic table interact, an ionic bond is the most likely outcome.