The matter which are called fluids.
Liquid and Gases
Fluidity : The ability to flow is called fluidity. The less force of attraction and more space
between particles make liquid and gas to flow. That’s why liquid and gas are called fluid.
Explanation for correct option: (d)
Liquid :
1.The spaces between the particles of a liquid are slightly more than that in a solid.
2.But it is not strong enough to hold the particles in liquids in fixed positions.
Gases: Gases have neither a fixed shape nor a fixed volume.
They do not have fixed boundaries. They can flow in all directions and can be easily compressed.
In a given space, the number of particles in gases are less than that in solids and liquids.
Explanation for incorrect option: (a)
Solid: Generally, all solids have a definite shape, distinct boundaries and fixed volumes i.e., have negligible
compressibility. Solids have a tendency to maintain their shape when subjected to outside force. This shows that they are rigid.
Liquid and Gases have less force of attraction and more space between particles make liquid and gas to flow.
There fore liquids and gases are called fluids.