What is the term for the ranking of materials based on their tendency to gain a charge?

The term that describes the ranking of materials based on their tendency to gain a charge is known as the electrostatic series. This series organizes materials according to their ability to lose or gain electrons, which ultimately determines how they will behave in electrostatic situations.

In the electrostatic series, materials that are more likely to gain electrons and acquire a negative charge are placed higher, whereas those that tend to lose electrons and acquire a positive charge are placed lower. This ranking is crucial for understanding various phenomena in electrostatics, such as how different materials interact with each other when they are brought into contact or are separated, leading to static electricity.

The other options do not accurately represent the ranking of materials by their charge-gaining tendency. A conductivity scale pertains to a material's ability to conduct electricity rather than its charge acquisition. A resistance chart relates to how much a material resists the flow of electric current, which is also different from gaining a charge. Charge potential is a vague term that doesn't specifically refer to the ranking of materials regarding their tendencies in electrostatic interactions.