How will a solution change if a base is added? The hydroxide ion concentration will decrease and lower the pH.
The hydroxide ion concentration will decrease and raise the pH.
The hydrogen ion concentration will increase and lower the pH.
The hydroxide ion concentration will increase and raise the pH.

As the concentration of hydrogen ions in a solution increase, the more acidic the solution becomes. As the level of hydroxide ions increases the more basic, or alkaline, the solution becomes. ... Thus, as the hydrogen ion concentration increases hydroxide ion concentration falls, and vice versa.

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the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.