physics models for class 9

Bohr improved upon Rutherford model postulating that electrons can revolve around the nucleus in certain discrete, non-radiating orbits, called stationary orbits, for which total angular momentum of revolving electron is an integral multiple of h / 2 p where h is Planck's constant. Where ..

'. The electrons are like plums in a pudding (positive charge). The seeds in a watermelon fruit can be given as a parallel comparison. With this model he tried to explain the observed spectra of elements. According to him, the vibrations of electrons would give rise to electromagnetic ene..

According to this model, an atom can be considered as a sphere of uniformly distributed positive charge in which there are electrons distributed symmetricall..

(i) Every atom consists of a nucleus containing the entire +ve charge. The whole mass of atom is concentrated at this core. (ii) The size of the nucleus i.e., 10 - 1 5 m is very small compared to the size of the atom (i.e., 10 - 1 0 m). (iii) The atom as a whole is electrically neutral wit..

The half life of radon is 3.8 days. Calculate how much radon will be left out of 10.24 milligram after 19 day..

- This is a representative list of topics covered in our Grade 9 Physics program - however all programs will be customized for the individual studen..

The scope of physics is very large. Physics deals with a wide variety of disciplines such as mechanics, heat and light. Study of mechanics helps us to know the forces involved in the flight of a bird, walk of a man and so on. The study of heat helps us to know the rise and fall..

Introduction - In the nineteenth century scientists saw enough evidence to prove that each element has its distinctive atom. But all tem atoms contain identical electrons. In spite of the fact that electrons carry negative charge, atoms as whole were found to be neutral. This led to the fact that a..

The solar system consists of sun, the nine planets and their satellites and thousands of other smaller heavenly bodies such as asteroids, comets and meteors. The sun is a star of intermediate size and luminosity. The sun appears to be larger and brighter than other stars because i..

A compound microscope is an optical instrument which is used to magnify very small objects like blood cells, bacteria which otherwise cannot be seen with the naked eye. A Laboratory Model of Compound Microscope The essential parts of a compound microscope are two convex lenses of short fo..