Ionic Bonding

An ionic bond is a bond formed between oppositely charged ions due to the strong electrostatic force of attraction. The formation of an ionic bond involves the following steps:

1. An atom, usually a metal, loses one or more electrons from its outer shell, which creates a positive ion. Another atom, typically a non-metal, gains one or more electrons, which forms a negative ion.

2. The oppositely charged ions are attracted to each other due to the electrostatic forces of attraction, forming an ionic bond.

3. The ionic bond is a strong bond that holds the ionic compound together.

Sodium Chloride: An Example of Ionic Bonding

To understand ionic bonding in sodium chloride, it’s important to know the structure of both sodium and chlorine atoms.

  • Sodium has one electron in its outer shell, which makes it unstable. To become stable, the sodium atom loses this electron, forming a positively charged sodium ion (Na+).
  • Chlorine has seven electrons in its outer shell, so there is space for one more electron. It is much easier to gain one electron than lose seven electrons, so the chlorine atom accepts an electron. Therefore, it becomes a negatively charged chloride ion (Cl).

There are electrostatic forces of attraction between the positive sodium ion and the negative chloride ion. This forms a strong ionic bond that holds the ionic compound together.

Dot and Cross Diagrams

A dot and cross diagram can show how electrons from the outer shells are transferred from a metal to a non-metal. For example, the dot and cross diagram below shows the transfer of electrons in the reaction between sodium (Na) and chlorine (Cl).

In the case of sodium (Na) and chlorine (Cl), the dot and cross diagram shows how the sodium atom loses one electron from its outer shell to form a sodium ion (Na+). Meanwhile, the chlorine atom gains one electron to form a chloride ion (Cl).

This diagram is a simple and effective way of showing the transfer of electrons. However, if you want, you can show all of the electron shells in your diagram.