PPT-The Atomic Mass Evaluation:

Present and Future WANG Meng Institute of Modern Physics CAS ARIS2014 Tokyo June 2 Outline Introduction atomic mass measurement evaluation Present status publication of . Mass of individual atoms. Lesson 1 – introduction to project and atomic structure. The Atomic mass unit (. amu. ). Atomic particle. Real mass (g). Relative mass (. amu. ). Proton p. +. #1: Rubidium has two common isotopes, . 85. Rb and . 87. Rb. . If the abundance of . 85. Rb is 72.2% and the abundance of . 87. Rb is 27.8%, what is the average atomic mass of rubidium?. PROCEDURE:. The lab technician shown here is using a magnifying lens to examine a bacterial culture in a petri dish. When scientists cannot see the details of what they study, they try to obtain experimental data that help fill in the picture.. I. Foundations of the Atomic Theory. A. 400 B.C. –Democritus. 1. Defined nature’s basic particles as . atoms. a. means indivisible. B. 350 B.C. Aristotle. 1. said matter was made of the 4 “elements”. Pre-AP Chemistry. Charles Page High School. Stephen L. Cotton . Section 4.1 Defining the Atom. OBJECTIVES:. Describe. Democritus’s ideas about atoms.. Section 4.1 Defining the Atom. OBJECTIVES:. Explain. Chapter 3. Types of Models – Why do we use models?. Physical Model vs. Conceptual Model. Physical model. is a representation of a very large or small object shown at a convenient scale. . Pre-AP Chemistry. Charles Page High School. Stephen L. Cotton . Section 4.1 Defining the Atom. The Greek philosopher . Democritus. He believed that atoms were . indivisible. . and . indestructible. Dalton’s Atomic Theory. Atomic Mass. What is an elements atomic mass?. The weighted average of its naturally occurring isotopes. .. When looking at an element on the periodic table of elements, where is atomic mass found?. Usually the top left hand corner of each elements box. However, on the periodic table that you will use for your AP Exam(s), this number will be located below each elements chemical symbol.. Steps for Calculating Average Atomic Mass. (. When given percentages of each isotope and each isotopes mass). 1. Convert the percentages into decimals. (This percentage is known as . its . relative . #1: Rubidium has two common isotopes, . 85. Rb and . 87. Rb. . If the abundance of . 85. Rb is 72.2% and the abundance of . 87. Rb is 27.8%, what is the average atomic mass of rubidium?. PROCEDURE:. Composition of Substances and Solutions Atomic Mass and Formula Mass; Mole & Molar Mass; Percent Composition of Compounds; Determination of Empirical & Molecular Formulas; Molarity Other Units for Solution Concentrations Over the past century scientist have discovered that the atom is composed of 3 subatomic particles:. Protons. Neutrons. Electrons. Checking for understanding. Draw this diagram. Label all subatomic particles and include their charges.. Daltons Atomic Theory. 1. All elements are composed of tiny . indivisible. particles called atoms.. 2. Atoms of the same element are identical. The atoms of one element are different from the atoms of another element.. In your notes…. Draw a model of an atom that best represents each component of that atom.. Foundations of Atomic Theory. Particle Theory of Matter. Democritus in 400 B.C.. Stated that nature’s basic particle was the atom (“indivisible” in Greek). .