PPT-Vector atom model Dr. Mahender

Singh Associate Professor in Physics PGGC 11 Chandigarh Vector model of an atom The total angular momentum of an atom result from the combination of the orbital and spin angular momenta of its electrons Angular momentum is a vector quantity so we can represent the total angular momentum by means of a vector J obtained by the addition of orbital angular momentum L and spin angular momentum S vectors This leads to the vector atom model . Lesson 1: Atomic Structure. Scientist. Contribution to Atomic Theory. Experiment. Atomic Structure. Chemistry 12: Chapter 4. Atomic Structure. You should be able to:. Discuss the development of the atom from earliest atomic theory to modern day theory of the atom. (around 400 BCE). Democritus thought matter could be divided into. . smaller and smaller pieces until a . single indivisible . particle is reached. . He named this particle the . atom. He proposed that atoms are of different sizes, in constant motion, and separated by empty spaces.. Atomos: Not to Be Cut. The History of . the Atom and the Atomic . Theory. Atomic Models. This model of the atom may look familiar to you. This is . the Bohr model. . In this model, the nucleus is orbited by electrons, which are in different energy levels. . Chemistry. Videos . Atomic Theory: Dalton, Democritus, Thomson, Rutherford, and Quantum. History of the . atom. . History of the atom Video #2. The Development of the Atomic Theory. J.J. Thomson . Contribution. model. Dr. . Mahender. Singh. Associate Professor in Physics. PGGC – 11 Chandigarh. Vector model of an atom. The total angular momentum of an atom result from the combination of the orbital and spin angular . Page 162. Super Model. Start a new thread/topic. Learning Target: How can you determine the structure of something you cannot see?. Update TOC. Super Model. Read Intro p. 162-163. Since we can’t see an atom, we are going to use different types of models to help us visualize atoms.. 4.1 Early Theories of . Matter (& Early Chemistry – Alchemy and Related). 4.2 Subatomic Particles & Nuclear Atom. 4.2.5 Ultimate Structure of Matter – The Standard Model (Not in Book). Section 4.1 Early Ideas About Matter. Five Experiments You Should Know. J. J. Thomson’s Cathode Ray. English physicist J. J. Thomson studied electrical discharges in partially evacuated tubes called . cathode-ray tubes. . He found that when high voltage was applied to the tube, a “ray” he called a . Two regions. Nucleus . protons and neutrons. Electron . cloud. region where you might find an electron. Modern View. . . . . . . .. Dalton (1803). Thomson (1904). (positive and negative charges). Atoms are the fundamental blocks of matter…. Chapter Big Idea. Section 1: Early Ideas About Matter. What are the similarities and differences of the atomic models of Democritus, Aristotle, and Dalton?. . Constituents . of the atom. J.J. Thomson. (1856-1940) . . In 1897 J.J. Thomson discovered the . electron. . This is a tiny negatively charged particle that is much, much smaller than any atom. He said that the tiny negatively charged electrons must be embedded in a cloud of positive charge. Thomson imagined the electrons as the bits of plum in a plum pudding, rather like currants spread through a Christmas pudding.. The Complete Modern Atom. An atom is:. mostly empty space. . nucleus has . most of . mass. of an atom . Atom is divisible. Protons (+1 charge). Neutrons (no charge). Electrons (-1 charge). nucleus contains protons & neutrons. Rutherford proposed that most of the mass of the atom was concentrated. . at the atom’s center. . Rutherford’s Model of the Atom. Rutherford’s experiment suggested that an atom’s positive charge is concentrated in the center of the atom . Known as the “Laughing Philosopher”. “Nothing exists except atoms and empty space; everything else is opinion.”. Created term “. atomos. ” which literally means “not cut” or indivisible.