The ability of a substance to conduct electricity depends on the presence of charged particles that can move freely. Pure water is a poor conductor of electricity because it does not contain a significant concentration of ions; it consists mainly of water molecules, which are neutral.
Pure salt (sodium chloride, NaCl) is also a poor conductor in its solid form because the ions are locked in a crystal lattice structure and cannot move freely. However, when salt is dissolved in water, the ionic bonds that hold the sodium (Na⁺) and chloride (Cl⁻) ions together break, allowing the ions to disperse throughout the solution.
Once dissolved, the Na⁺ and Cl⁻ ions become free to move in the water, which allows the solution to conduct electricity effectively. This is because the movement of these charged ions can carry electric current through the solution.
In summary, the statement that explains why the resulting saltwater solution conducts electricity well is: When salt dissolves in water, it dissociates into free-moving ions, which can carry electric charge, allowing the solution to conduct electricity.