Final answer:
Electrolytes are substances that can carry an electrical current across cell membranes when dissolved in water. These are ionic compounds that dissociate into ions such as sodium ions (Na+) and chloride ions (Cl-) which are crucial for bodily functions.
Step-by-step explanation:
Substances that can carry electrical current across cell membranes are called electrolytes. Electrolytes are compounds that conduct an electric current when they are in an aqueous solution or melted. Ionic compounds like sodium chloride (table salt) dissolve into ions in water, becoming sodium ions (Na+) and chloride ions (Cl-), which are essential for various physiological processes in the human body.
These ions are mobile in the dissolved state and can move from one electrode to the other, which is necessary for conducting electricity. Substances with free mobile ions that carry an electrical charge, not the electrons, in a solution allow an electric current to pass through, making them vital in fields such as medicine and chemistry.