What effect does increased acidity have on pH levels?

Increased acidity directly correlates with a decrease in pH levels. The pH scale measures the concentration of hydrogen ions in a solution, where a lower pH value indicates higher acidity due to a greater concentration of hydrogen ions. Therefore, when the acidity of a solution increases, the pH level drops. This concept is fundamental in understanding the behavior of acids and bases in chemistry, particularly in fields like cosmetology and skin care, where the pH of products can significantly affect their efficacy and interaction with the skin. Thus, the assertion that increased acidity lowers pH levels accurately reflects the relationship defined by the pH scale.