Question

Give reason: Liquids and gases flow but solids do not?

Answer 1

Hint: Any substance occupying space and has a mass can be termed as matter. Matter is broadly distinguished into three major forms on the basis of the differences in their bulk properties and intermolecular forces namely solids, liquids and gases.

Complete step by step answer:
Solids can be characterized by a definite volume and shape. Liquids can be characterized by their ability to adapt to the shape of the container they are kept in and gases can be characterized by their ability to adapt to the shape as well as the volume of the container they are stored in.

The molecules of gases and liquids are present far apart from each other. In other words, they have more gaps or intermolecular spaces. Due to the large intermolecular forces, the intermolecular attractions are very less and thus liquids and gases can flow. On the other hand, solids have very less intermolecular spaces. The intermolecular forces are high giving them a definite shape and making it rigid. Thus, solids do not flow.

Note:
We know that solids do not flow. However, amorphous solids have a tendency to flow at a very slow rate. They are commonly known as pseudo solids or super cooled liquids due to this property. A common example is a glass panel fixed to a window or door of a very old building. If they are observed carefully, we will find that the glass is slightly thicker at the bottom than that at the top. The reason for this is that glass is an amorphous solid and flows very slowly under the influence of gravity making the lower portion of the panel thicker than the upper.