modern atomic theory

Atoms and Molecules - Laws of Chemical Combination With the development of more scientific ideas on elements, compounds and mixtures, people began to probe into how and why substances react. French chemist A. Lavoisier laid the foundation to the scientific investigation of matter by descr..

Atoms And Molecules From the earliest times, man has always wondered about the ultimate nature of matter. He has searched to establish the basic constituents of all the substances. However, earlier efforts were more in the nature of speculations and not based on scientific investigati..

Summary The law of conservation of mass states that the masses of the reactants and products remain unchanged. The law of constant proportions states that all pure specimens of a compound always contain the same elements combined together in the same proportion by weight. According to Da..

Heat and Motion (Kinetic Theory of Heat) - Under normal conditions matter exists in three forms: solid liquid gas Matter is made up of atoms and molecules. These atoms in molecules are in a state of continuous motion. For example, molecules and atoms of a sol..

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 nucleus. He suggested that atomic number is a more fun..

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 nucleus. He suggested that atomic number is a more fundamen..

Quantum Mechanical Model of the Atom - Two new theories came to substantially modify Bohr's Atomic model. They a..

Rutherford's model had a major drawback. It could not explain why ultimately electrons did not fall into the nucleus by taking a spiral path. This was in concurrence with the electromagnetic theory that states 'if a charged particle undergoes accelerated motion then it must radiate ..

Introduction - The evidence of the electrical nature of matter preceeded the first theories about the structure of matter. In 1832, Michael Faraday discovered electrolysis. He gave the first important clue relating electricity to matter and about the electric nature of atoms. Fa..

Rutherford proposed that electrons revolve at high speed in circular orbits around the positively charged nucleus. But according to the electromagnetic theory, if a charged particle were accelerated around another charged particle then there would be a continuous radiation of energy. Th..