study the physical property of metals and non metals with information

In the chapter on current electricity, we had learnt about the flow of charges, conditions to produce the flow and how different materials respond to an external electric field. We had seen how materials are classified as conductors and insulators. In this chapter, we will study a new typ..

Mechanical properties like strength, stiffness (Rigidity), ductility, malleability and brittleness have to be carefully studied to select a material for a particular job. The metallic parts of machines should not be subjected to stress beyond the elastic limit other..

. where r , called resistivity is a property of the material and depends on temperature and pressure. Electrical resistivity of substances varies over a very wide range. Metals have low resistivity, in the range of 10 - 8 W m to 10 - 6 W m. Insulators like glass and rubber have ..

. The energy received by the electrons helps it to escape from the surface of the metal and to do this the electron loses an amount of energy called as the work function of the surface of the metal ( f ). Therefore, if the energy received by the electron from photon is h u [equa..

In 1819, two French physicists Dulong and Petit discovered that the average molar specific heat at constant pressure for all metals, except the very light ones, is approximately the same and equal to nearly 25 J mole -1 o C -1 . Although the law is an approximate one, it conveys a very im..

The specific heat of a substance is an important physical property because it tells us the suitability of a given substance for a specific purpose. Aluminium vessels are used in cooking because aluminium is a light metal. Hence, for a given volume, its thermal ca..

There are three ways in which electrons eject out of a material. They are (i) Thermionic emission (ii) Field emission (iii) Photo electric emission In all the above cases, energy is given to the material but in different forms. If given in the form of heat it is called as Thermionic emission, if in..

The minimum amount of energy required to emit electrons from a metal surface is called the work function or threshold energy of that metal. The number of electrons emitted per second i.e. the rate of emission depends upon the material of the surface temperature of the surfa..

Applications of Photoelectric Cells - Photocells are used in television camera to reproduce sound recorded on films, in counting devices, in burglar and fire alarms, to measure the temperature of stars, to study the spectrum of heavy bodies, to operate street light, to compare the illumin..

In 1834, Michael Faraday studied the passage of electricity through liquids. He called it electrolysis, as it was accompanied by the chemical decomposition of the electrolyte. The term lysis in Greek means setting free. The metallic conductors through which the current enters an..