What does the hydrogen ion (H+) indicate?

The hydrogen ion (H+) is a fundamental concept in chemistry, particularly in acid-base reactions. When acids dissociate in solution, they release hydrogen ions. This dissociation is what characterizes an acid; when an acid dissolves in water, it increases the concentration of H+ ions in that solution, which directly correlates to the solution's acidity.

In this context, option B correctly identifies that an excess of H+ ions is produced when acids dissociate. This is crucial for understanding pH, where the concentration of hydrogen ions determines the acidity of a solution.

On the other hand, the other options do not accurately describe the nature of hydrogen ions or their role in chemical processes. A suggests a scenario that relates to negative charge rather than an understanding of H+ as a positive ion. C incorrectly implies that H+ is neutral, which contradicts its very definition as a positively charged ion. D mischaracterizes H+ by referring to it as a stable molecule; instead, H+ is a simple ion, crucial for acidity but not a stable molecule on its own. Therefore, option B is the appropriate interpretation in the context of the behavior of acids in solution.