modern atomic theory

The indivisibility of an atom was proved wrong, for, an atom can be further subdivided into protons, neutrons and electrons. However an atom is the smallest particle, which takes part in chemical reactions. According to Dalton, the atoms of same element ..

Although Dalton's theory of the existence of atoms was published in 1808 there was no clear idea of what an atom might look like until the early part of the twentieth century. With the advent of electricity and phenomenon of spectrum, experimentation underwent a ..

Although Dalton's theory of the existence of atoms was published in 1808 there was no clear idea of what an atom might look like until the early part of the twentieth century. With the advent of electricity and phenomenon of spectrum, experimentation underwent a change..

. In 1793, he left for Manchester to teach physics and chemistry in a college. In 1801, he observed and discovered the law of expansion of gases on heating. He also enunciated the law of partial pressures and found methods of determining vapour pressure of gases. He invented the dew point hygromete..

Modern Periodic Table-Long Form Periodic Table of Elements - Later, Henry Gywn-Jeffreys Moseley showed that the atomic number of an element is numerically equal to the number of electrons round the nucleus. The number of electrons in turn is equal to the number of protons in the..

Trends in the Modern Periodic Table - The periodic trends of the following properties are studied here. Atomic size Metallic and Non-metallic character Ionization potential Electron affinity Electronegativi..

>When a nucleus emits radiation it is said to decay. Rays from radioactive isotopes are dangerous to living things but are also useful in variety of ways. Exposure to large amounts of radiation is harmful to health. All radioactive materials should always be handled with care and kept inside lead b..

A completely satisfactory theory of magnetism has still not been formulated. At present it is assumed that magnetism is due to the movement of the electrons. The electrons circulate around the nucleus of the atom..

Theory of Magnetism - A completely satisfactory theory of magnetism has still not been formulated. At present it is assumed that magnetism is due to the movement of the electrons. The electrons circulate around the nucleus of the atom. They also spin around an axis thr..

1. The modern periodic table is divided into two main categories: (i) Vertical columns called Groups and (ii) Horizontal columns called Periods. 2. There are 18 vertical columns or groups. These are further sub-divided into A and B (groups I to VII), VIII group and zero group..