The largest application of tantalum is in electronic components made from tantalum powder, mainly capacitors and high-power resistors. Tantalum electrolytic capacitors utilize the principle that tantalum is able to form a protective oxide layer, using the tantalum powder pressed into a round ball shape as one of the "bias plates", its oxide as the dielectric, and an electrolyte solution or a solid conductor of electricity as the other "bias plate". Since the dielectric layer is very thin, a very high capacitance per unit volume can be achieved. Such capacitors are small in size and light in weight, making them ideal for use as electronic components in cellular telephones, computers, and automobiles.