Question

what is vacuum flask​

Answer 1

Answer:

A container like a bottle with double walls with an empty space (vacuum) between them, used for keeping liquids hot or cold

Answer 2

Vacuum is a poor conductor of heat, it limits heat loss by conduction.

Explanation:

• A vacuum flask, often known as a thermos flask, is a super-protected jug or container. The internal chamber and the external plastic or metal case of most vacuum flasks are separated by two layers of glass with a vacuum in the middle.
• To reflect heat, the interior surface of glass is usually lined with a thin reflecting metal coating. Some vacuum flasks employ stainless steel instead of glass for increased durability; they feature two layers of stainless steel with a vacuum and a reflective layer in the centre.
• On the top, there's also a stopper, which is a tight screw-down. These few, essential components keep heat from escaping through conduction, convection, or radiation. Conduction is prevented by the vacuum, which is a poor conductor of heat.