PPT-Specification: Simple model of the atom, including the proton, neutron and electron.

Constituents of the atom JJ Thomson 18561940 In 1897 JJ 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. 2 Neutron Reflectometers Updates prepared by Helmut Fritzsche and Zin Tun Canadian Neutron Beam Centre A neutron reflectometer yields data to determine th e scatteringlength density profile of a flat sample as a functi precision measurements: what do they provide?. precision experiments part of large facilities. precision experiments with neutrons. Precision experiments. Electroweak precision experiments. proton decay measurements. Saturday Physics for Everyone. November 9, 2013. (With debts to Chris Quigg, Leonard Susskind, Hitoshi Murayama). Why is there mass?. What . is mass?. Mass is . stuff. Mass is the . stuff. that gravity acts on. What are the 3 major parts of an atom?. Proton . Neutron . Electron. Parts of an Atom. Another Model. SIMPLIFIED MODEL.. PROTON. Protons are positively charged particles found in the atomic nucleus. . . Beta decay. seen at quark level. . . A quark emits a W or W- and changes its flavor (type).. . Beta decay. leading a positron. It travels a short distance before encountering an electron in the material, where it annihilates to two gamma rays (photons) of .511 MeV each.. APS March Meeting, Mar 14, 2017. John S. Colton. Physics Department. Brigham Young University. Co-authors:. . J. . S. . Embley. ,* . K. G. Miller, M. A. Morris. ,* . M. Meehan, S. L. . Crossen. Students at BYU. 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. 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). Chemistry. Basics of the Atom . Subatomic. Particle. Charge. Location in. the Atom. Mass. a.m.u.. : unit used to measure mass of atoms. “atomic mass unit”. proton. neutron. electron. 1 . 0. 1–. Part I. . Unstable. vs. . stable. nuclei: . neutron-rich. and . proton-rich. . systems. Limit of . nuclear. . stability. and . definition. of . drip. . lines. From: Exotic Nuclei, J. Enders, TU Darmstadt, Summer 2003. W. . Reviol, D. Rudolph, D.G. Sarantites, . C.J. Chiara. , D. . . Seweryniak. Washington . U. / Lund U. / U. of Maryland / ANL. Gretina Workshop, . ANL, . March . 2013. Neutron-Shell . Detectors. 35 hexagonal, tapered detectors.. 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. . Bohr’s Model . Niels. Bohr suggested that the problem about hydrogen spectrum can be solved if we can make some assumptions. . According to classical theory, the frequency of the electromagnetic waves emitted by a revolving electron is equal to the frequency of revolution. . 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.