The lemon is a small evergreen tree originally native to Asia, and is also the name of the tree’s oval yellow fruit. The fruit is used for culinary and nonculinary purposes throughout the world – primarily for its juice, though the pulp and rind are also used, mainly in cooking and baking. Lemon juice is about 5% citric acid, which gives lemons a sour taste, and a pH of 2 to 3. This makes lemon juice an inexpensive, readily available acid for use in educational science experiments. Because of the sour flavor, many lemon-flavored drinks and candies are available, including lemonade.