Question

Explain why solids have fixed shape but liquid and gases do not have fixed shape.

Answer 1

Hint: Solids are generally rigid and compact whereas liquids and gases are free in shape i.e. they can take any shape and this particular behavior could be explained on the basis of their properties like intermolecular forces of attraction, the type of packing in them. These properties comparison could take to the answer easily.

Complete step by step answer:
In the question asked, the properties of solids, liquid and gases are compared and these properties if compared can answer the given question. We will look upon the properties of these which will take to the answer.
-Solids are those substances which have definite shape, volume and these are rigid structures and the intermolecular forces of attraction are very high i.e. the atoms are very close to each other giving the whole structure as rigid one.
-Liquids are those substances which have definite volume but not fixed shape because the intermolecular forces of attraction are very less compared to solids i.e. atoms of liquid are far away from each other making them unfixed in shape. They are arranged such that they can take any shape when required.
-Gases are substances with indefinite shape and the forces of attraction are least compared to solids and liquids and the atoms are far apart in that they don’t have any fixed shape.
These are the 3 main states of matter and their shape properties could be defined only by the intermolecular forces of attraction between them.
Intermolecular forces of attraction solids are very high and the particles are very close to each other making them compact and rigid. So, the solids have definite shape compared to liquids and gases.

Note:
There are different properties of these which could be compared like density, existence, stability etc. and if talking about solid particularly, there are two different types of solids which are Crystalline solid and Amorphous solid. These solids, liquids, and gases are different states of matter but as of now there are two more states of matter which are plasma and Bose-Einstein condensate. So, there are a total 5 states of matter as of now.