Lemon

The lemon (Citrus × limon) is a hybrid in cultivated wild plants. It is the common name for the reproductive tissue surrounding the seed of the angiosperm lemon tree. The fruit are used primarily for their juice, though the pulp and rind (zest) are also used, primarily in cooking and baking. Lemon juice is about 5% acid, which gives lemons a sour taste and a pH of 2 to 3. This makes lemon juice a cheap, readily available acid for use in educational science experiments.