Kinetic Theory of Matter
Matter is made up of tiny particles such as atoms, molecules and ions. These particles are continually moving, so they possess kinetic energy.
The constant motion of the discrete particles of matter forms the basis for the kinetic molecular theory of matter.
States of Matter
Matter exists in three physical states: Solid, Liquid and Gas.
A Solid has a definite shape, Liquid takes the shape of its container and Gas has no shape.
Matter can change from one state to another i.e from solid to liquid and from liquid to gas.
In a solid-state, the molecules are very close together and their movement is restricted. This makes solids have a fixed shape. The cohesive forces binding the solids are very strong. Solids also have definite volume and are not easily compressed.
The liquid flows and takes the shape of the container. The movement of the molecules is less restricted than the solid-state, i.e they have more kinetic energy than the solid.
In a gaseous state, the particles have more kinetic energy than the liquid. The molecules of a gas are the least restricted. The molecules move so fast that the attractive force between them is very weak. A gas has no definite shape.
In general, gas molecules possess more kinetic energy than liquid molecules which possess more kinetic energy than the solid molecules.
Properties of Solid, Liquid and Gases
|1||Fixed shape||No fixed shape. (takes the shape of the container)||No fixed shape|
|2||Cannot be compressed||Cannot be compressed||Easily compressed|
|3||Movement restricted||Movement less restricted||Movement least restricted|
|4||Fixed mass||Fixed mass||Fixed mass|
|5||Fixed volume||Fixed volume||No fixed volume|
|6||Very dense||Less dense||Least dense|