@greenrun, A substance can be divided into parts (particles) whose particle size is smaller. The smallest particles of a substance that still have properties equal to the nature of the origin of the particle are called a molecule. The compound of this molecule can be a bond between the same elements (molecular unsure), but can also be a bond between different elements (molecules of the compound). If a compound is electrolyzed with a direct electric current it will be ionized. Particles of these ionized compounds are called ions. Ions are particles that are electrically charged. Anions are negatively charged electric ions, whereas cations are positively charged ions. They are all material particles.