Here's why:

* pH Scale: The pH scale measures the acidity or alkalinity of a solution. It ranges from 0 to 14.

* Acids: Acids have a higher concentration of hydrogen ions (H+) than hydroxide ions (OH-). This means their pH value is lower than 7.

* Bases: Bases have a lower concentration of hydrogen ions (H+) and a higher concentration of hydroxide ions (OH-). Their pH value is higher than 7.

Therefore, a solution with a higher hydrogen concentration will have a lower pH value and will be considered acidic.