Final answer:
The pH of healthy skin is slightly acidic, between 4.5 and 5.5, which supports its function and the microbial community on its surface. The pH scale measures the acidity or alkalinity of substances, with 7 being neutral. Other bodily fluids have varying pH levels, such as the blood's slightly alkaline pH of around 7.4.
Step-by-step explanation:
The question relates to the pH level of healthy skin, which is defined to be between 4.5 and 5.5. The pH scale is a measure of how acidic or basic (alkaline) a substance is. Neutral substances, like water, have a pH of 7. Healthy skin has a pH that is slightly acidic to help maintain its barrier function and support the natural microorganisms that live on the surface. In comparison, other bodily fluids and substances have different pH levels, such as the blood which is slightly alkaline with a pH of around 7.4, and stomach acid which is highly acidic with a pH between 1 to 2. The pH scale is logarithmic, meaning each whole number change represents a ten-fold increase or decrease in hydrogen ion concentration (H+). Significant in environmental science as well, the pH of rainwater and seawater are also discussed in relation to their respective ranges due to their importance in the balance of natural ecosystems.