flask

A flask is a type of bottle that is used in science labs. It is usually made of glass or plastic, and it has a long neck with a narrow opening. Flasks are used to hold liquids, gases, and solids. They can also be used to heat or cool substances.

Flasks come in many different sizes. Some flasks are very small, while others are very large. The size of the flask depends on what it will be used for.

Flasks are an important tool in science labs. They are used in many different experiments. For example, flasks are used to make solutions, to heat chemicals, and to store samples.

The hiker filled his flask with water.