Question

fixed positions.
2. (a) Define liquid.
(b) On the basis of molecular theory, explain
why liquids have a definite volume, but no
definite shape.
3. How can a solid be changed into liquid state?
Explain on the basis of molecular theory.
4. Describe the processes involved in changing a
gas into a liquid and further a liquid into a solid.
Explain the possible conditions briefly.
5. (a) Define diffusion.
(b) How is diffusion varied for three different
states of matter?​

Answer 1

1. liquid is a substance which does not have a fixed shape but fixed volume.

2. on the basis of molecular theory liquid have a fixed volume but not a fixed shape because they have more interparticle space and mostly have less density and particles can move freely.

3. solid can be changed into a liquid state by the process of melting.

4. gas changes to liquid by the process of condensation in the process of condensation gas convert into liquid example water vapour get condense on the surface of glass containing chilled water and liquid changes into solid by the process of freezing in the freezing the liquid converts into solid example convert water into ice in fridge in ice tray.

5(a). diffusion means the intermixing of particles of two different types on their own.

(b). diffusion takes place most rapidly in gases

the particle of gas have more kinetic energy due to that they move with high speed. because of the movement of particles with high speed gas diffuse most rapidly. example mixing of gases in air.

diffusion in liquid:

the particles of liquid having a moment because a kinetic energy for diffusion where two liquids are kept together they are mixed because of diffusion for example when salt solution is kept in water this makes whole the solution salty after some time this happens because of diffusion in liquid.

diffusion in solid:

diffusion takes place with lowest rate in the case of solids the rate of diffusion is almost negligible in solids full stop since the particles of solid have slowest kinetic energy so they do not move. hens diffusion takes a long time in space of solid. example some time we observe that the marks of chalk on a blackboard could not be wiped out isliye after a long time. this happens because of diffusion of particles of jobs with the particles of blackboard and mark of chauk could not be wiped out.

Answer 2

Answer (a) Liquid is a chemically flowing substance that can flow freely.It has fixed volume but no fixed shape. They always take the shape of the containing vessel.Liquids need container to hold them.