An increase in hydrogen atoms will cause a decrease in pH.

pH is a measure of the acidity or basicity of a solution. It is determined by the concentration of hydrogen ions (H+) in the solution. The more hydrogen ions there are, the lower the pH. Conversely, the fewer hydrogen ions there are, the higher the pH.

So, if the number of hydrogen atoms in a solution increases, it means that there will be more hydrogen ions. This will cause the pH of the solution to decrease.