When the amount of hydrogen ion in a solution is increased, the pH of the solution will be \(\boxed{\text{decreased}}\).
In a solution with a pH of 7.0, the amount of hydrogen ions is \(\boxed{\text{equal to}}\) the number of hydroxide ions \((\mathrm{OH}^{-})\).
A solution with a pH below 7.0 is considered \(\boxed{\text{acidic}}\).