Ionic compounds conduct electricity because of the movement of charged particles, specifically ions, within the compound. This conductivity occurs in the molten state or when the compound is dissolved in water, as it allows the ions to move freely and carry electric charge.
When an ionic compound is molten or dissolved in water, its solid lattice structure breaks down. In the molten state, the compound is heated to a temperature where the ionic bonds between the positively and negatively charged ions are weakened, allowing the ions to move more freely. Similarly, when an ionic compound is dissolved in water, the water molecules surround the ions and help to separate them, allowing them to move independently.
In both cases, the mobile ions are able to carry an electric charge. This is because the ions themselves are charged particles. Ionic compounds are made up of positive ions, called cations, and negative ions, called anions. These ions are formed when atoms gain or lose electrons to achieve a stable electron configuration. The cations have a positive charge because they have lost electrons, while the anions have a negative charge because they have gained electrons.
When an electric potential is applied across the molten or aqueous solution of an ionic compound, the cations and anions are attracted to opposite electrodes. The cations move towards the negatively charged electrode (cathode), while the anions move towards the positively charged electrode (anode). This movement of the charged ions creates an electric current, allowing the compound to conduct electricity.
It is important to note that in the solid state, where the ionic compound is not molten or dissolved, it does not conduct electricity. This is because the ions are held in a fixed lattice structure and are not free to move. The movement of ions is necessary for the flow of electric charge.
To further understand the concept of ionic compound conductivity, let’s consider a practical example. Imagine a simple ionic compound like table salt (sodium chloride). In its solid state, table salt does not conduct electricity. However, if we melt the salt or dissolve it in water, the resulting substance can conduct electricity. This is because the sodium ions (Na+) and chloride ions (Cl-) can move freely in the molten or aqueous solution, allowing the flow of electric charge.
The conductivity of ionic compounds is attributed to the ability of the ions to move freely in the molten state or when dissolved in water. This movement of charged particles enables the flow of electric current, making the compound conductive.