You probably already know that an acid is the opposite of a base, but did you know that there are three acid-base concepts? That is to say, there are three ideas about what makes an acid and what makes a base.
The three acid-base concepts are:
These three concepts do not contradict each other, but rather they complement each other. The three acid-base concepts actually follow an evolution in acid-base thought. All three acid-base concepts were developed some time ago, but they are all still in use today.
Salts are grouped with acids and nases and you will discover why later in this lesson. Before considering the three acid-base concepts, let's first look at general properties of acids, nases, and salts.