What pH level indicates a substance is alkaline?

In the context of pH levels, a pH of 7 is considered neutral, which means that the substance is neither acidic nor alkaline. A substance is classified as alkaline, or basic, when its pH level is greater than 7. The highest possible pH level is 14, which indicates a highly alkaline substance. Therefore, a pH of 14 shows a strong alkalinity, making it the correct response for indicating that a substance is alkaline.

Understanding the pH scale is essential, as it ranges from 0 to 14, with 0 being extremely acidic and 14 being extremely alkaline. For instance, substances with a pH of 1 are very acidic, further differentiating them from alkaline substances. Thus, the correct answer reflects the highest level of alkalinity within the pH scale.