What term describes a substance that has a pH greater than 7?

A substance that has a pH greater than 7 is referred to as alkaline or basic. In the context of pH levels, a pH of 7 is considered neutral, while values below 7 indicate acidity. As pH increases above 7, the substance becomes less acidic and more alkaline.

Both "alkaline" and "basic" essentially describe the same property, which is the tendency of a substance to accept protons or donate electron pairs. Alkaline substances typically have higher concentrations of hydroxide ions (OH⁻) compared to hydrogen ions (H⁺). Common examples of alkaline substances include sodium hydroxide and baking soda, which can neutralize acids.

While the options presented include "acidic" which clearly defines substances that have a pH lower than 7, and "neutral," which is purely 7, the terms "alkaline" and "basic" correctly designate substances with a pH above 7. Since both these terms can describe the property of a substance with a pH greater than 7, "alkaline" is a suitable and specific descriptor in this context. Thus, selecting "alkaline" aligns with the scientific understanding of pH and its classifications.