On the pH scale, what range represents acidic substances?

The correct choice identifies the range of the pH scale that indicates acidic substances, which is from 0 to 7. The pH scale quantifies the acidity or alkalinity of a solution, with lower values denoting higher acidity. A pH of 7 is considered neutral, meaning the solution is neither acidic nor basic. Therefore, any pH value below 7 signifies an acidic environment, with the extent of acidity increasing as the number decreases toward 0.

While other ranges refer to narrower segments of the scale, they do not encompass the full spectrum of acidic values. For instance, the range from 4.7 to 5.5 is specific but does not represent all possible acidic conditions. Similarly, the ranges from 7 to 14 indicate basic or alkaline substances, while 5.5 to 7 approaches neutrality but still does not sufficiently represent acidity. Thus, the broad range of 0 to 7 captures all acidic characteristics comprehensively.