Is string bean a mixture or pure substance?

A mixture is a material composed of two or more substances (elements or compounds) that are physically mixed but not chemically combined. Mixtures can be separated into their component substances by physical means, such as filtration, distillation, or chromatography.

A pure substance is a material that has a uniform composition and is made up of only one type of atom or molecule. Pure substances cannot be separated into simpler substances by physical means.

String beans are a type of vegetable that is composed of plant cells. Plant cells are made up of various compounds, including water, proteins, carbohydrates, and minerals. However, string beans do not contain any other substances that are not found in plant cells. Therefore, string beans are a pure substance.