DOCSLIB.ORG

Lecture Presentation Chapter 4

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lecture Presentation Chapter 4 Lecture Presentation Chapter 4 4.1 – Elements and Symbols 4.2 – The Periodic Table 4.3 – The Atom 4.4 – Atomic Number and Mass Number 4.5 – Isotopes and Atomic Mass 4.6 – Electron Energy Levels 4.7 – Electron Configurations 4.8 – Trends in Periodic Properties General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Goal : Given its name, write its correct symbol; from the symbol. Write the correct name. Elements: are pure substances from which all other things are built. are listed on the periodic table. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Element names come from planets, mythological figures, minerals, colors, geographic locations, and famous people. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Chemical symbols Carbon, C • represent the names of the elements. • consist of one to two letters and start with a capital letter. One-Letter Symbols Two-Letter Symbols C carbon Co cobalt N nitrogen Ca calcium F fluorine Al aluminum O oxygen Mg magnesium General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Write the correct chemical symbols for each of the following elements: A. iodine B. iron C. magnesium D. zinc E. nitrogen General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Give the names of the elements with the following symbols: A. P B. Al C. Mn D. H E. K General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Mercury (Hg) Is a silvery, shiny element that is liquid at room temperature. Can enter the body by: mercury vapor inhalation contact with the skin ingestion of water or food contaminated with mercury Once mercury has entered the body, it destroys proteins, disrupts cell function. Long-term exposure can Damage the brain and kidneys Cause mental retardation Decrease physical development General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Mercury contamination comes from • industrial wastes. • fish and seafood. • batteries. • compact fluorescent bulbs. Fish absorb mercury. Big fish eat lots of small fish, end up with more mercury. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake 4.1 – Elements and Symbols 4.2 – The Periodic Table 4.3 – The Atom 4.4 – Atomic Number and Mass Number 4.5 – Isotopes and Atomic Mass 4.6 – Electron Energy Levels 4.7 – Electron Configurations 4.8 – Trends in Periodic Properties General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Goal : Use the periodic table to identify the group and the period of an element; identify the element as a metal, a nonmetal, or a metalloid. The Periodic Table The periodic table organizes 118 elements into groups with similar properties and places them in order of increasing atomic mass. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Groups and Periods In the periodic table, elements are arranged according to properties. Vertical columns represent groups of elements and horizontal rows represent periods. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Groups and Periods Group numbers are written at the top of each vertical column (1-18). Periods are numbered 1-7 General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Metals, Nonmetals, and Metalloids The heavy zigzag line separates metals and nonmetals. • Metals are located to the left. • Nonmetals are located to the right. • Metalloids are located along the heavy zigzag line. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Silver Metals (Metal) Nonmetals Solid at room temp Dull (not shiny / ) Exception: mercury brittle Shiny! Not ductile Ductile (shaped into wires) Not malleable Malleable (hammered Poor conductors flat into sheets) Low melting points Good conductors Low densities (many are High melting points gasses at room temp.) Antimony Sulfur (metalloid) (nonmetal) Metalloids have a combination of metal and nonmetal properties. Characteristics of Metalloids Silver (Metal) Metalloids, located along the heavy zigzag line on the periodic table exhibit properties of metals and nonmetals. • are better conductors than nonmetals but not as good as metals. • are used as semiconductors and insulators, because they can be modified to function as conductors or insulators. Antimony Sulfur (metalloid) (nonmetal) General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Study Check Identify each of the following elements as a metal, a nonmetal, or a metalloid: A. sodium B. chlorine C. silicon D. iron E. carbon General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Study Check List all of the elements that match the B. nonmetals in Group 15 description. Bi, N, P, As, Sb A. metals in Group 14 C. metalloids in Group 14 Sn, Pb, C, Si, Ge C, Si, Ge, Sn, Pb Group Names General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Alkali Metals Group 1, the alkali metals, includes the following: Soft • lithium (Li) Shiny Good • sodium (Na) conductors • potassium (K) Low melting • rubidium (Rb) points React • cesium (Cs) vigorously with • Francium (Fr) water! General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Alkaline Earth Metals Group 2 elements, the alkaline earth metals, are shiny but not as reactive as Group 1A metals. They include the following: • beryllium (Be) • magnesium (Mg) • calcium (Ca) • strontium (Sr) • barium (Ba) • radium (Ra) Strontium gives the red color in fireworks. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Halogens Group 17, the halogens, includes the following: • fluorine (F) • chlorine (Cl) • bromine (Br) • iodine (I) • astatine (At) General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Noble Gases Group 18, the noble gases, include: Helium (He) Neon (Ne) Argon (Ar) Krypton (Kr) Xenon (Xe) Radon (Rn) General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Study Check Identify the element described by each of the following groups and periods: 1. Group 17, Period 4 2. Group 2, Period 3 3. Group 15, Period 2 General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake FYI: Elements Essential to Health Of all the elements, 23 are essential for the well-being and survival of the human body. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake 4.1 – Elements and Symbols 4.2 –The Periodic Table 4.3 – The Atom 4.4 – Atomic Number and Mass Number 4.5 – Isotopes and Atomic Mass 4.6 – Electron Energy Levels 4.7 – Electron Configurations 4.8 – Trends in Periodic Properties General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Goal : Describe the electrical charge and location in an atom for a proton, a neutron, and an electron The Atom An atom is the smallest particle of an element that retains the characteristics of that element. Aluminum foil contains atoms of aluminum. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Atoms are made of subatomic particles Atoms contain the following subatomic particles: • Protons • Neutrons • Electrons General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Atoms are made of subatomic particles Atoms contain the following subatomic particles: • protons have a positive (+) charge • neutrons have no charge (neutral) • electrons have a negative (-) charge General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Structure of the Atom An atom consists of a nucleus, located in the center of the atom, that contains protons and neutrons and represents most of the mass of an atom. electrons that occupy a large, empty space around the nucleus. Protons – positive charge Neutrons – neutral Electrons – negative charge General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Structure of the Atom In an atom, the protons and neutrons that make up almost all the mass are packed into the tiny volume of the nucleus. The rapidly moving electrons (negative charge) surround the nucleus and account for the large volume of the atom. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Dalton’s Atomic Theory In Dalton䇻s atomic theory, atoms • are tiny particles of matter. • of an element are similar to each other and different from those of other elements. • of two or more different elements combine to form compounds. • are rearranged to form new combinations in a chemical reaction. Atoms are never created or destroyed during a chemical reaction. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Mass of the Atom Because the mass of subatomic particles are so small, • chemists use a very small unit of mass called the atomic mass unit (amu). • 1 amu has a mass equal to 1/12 of the mass of the carbon-12 atom that contains six protons and six neutrons.
Load more

Recommended publications
  • CHEM 1A: Exam 1 Practice Problems
    CHEM 1A: Exam 1 Practice Problems: These practice problems are not a comprehensive list of all questions to be asked on the exam. Refer to the suggested textbook HW, other practice problems on the review page, iclicker questions, & challenge problem sets for a comprehensive review. Unit Conversions & Dimensional Analysis: 65.3 g of Iron → _______________ mol Iron 12 3.97 x 10 CO2 molecules →_______________ mol CO2 0.783 mol of CH3CH2OH →_______________ mL of CH3CH2OH Reference Information: Density = 0.789 g/mL The density of a sample of propane (C3H8) gas is 1.80 g/L. How many molecules of propane are contained in a 1.50 L balloon? What about the total number of atoms? 1.097 x 10-2 nm-1 → _______________ m-1 True or False: A gram of magnesium contains more atoms than a gram of calcium. Each conversion below involves at least one mistake. Can you identify the mistakes and correct them? Corrected Conversions: 5.98 푚표푙 1 퐿 1 푚퐿 푚표푙 = ? 퐿 10−3푚퐿 1 푐푚3 푐푚3 ________________________________________________________________________________________________________________________________________________________________________________________________________________________ 0.087 푛푚 1 푚 1 푚푚 = ? 푚푚 1 10−9푛푚 103푚 ________________________________________________________________________________________________________________________________________________________________________________________________________________________ 7.874 푔 1 푘푔 (10−2푐푚)3 푘푔 = ? 푐푚3 10−3푔 (1 푚)3 푚3 Nomenclature & Formulas Which of the following compounds contains the cation with the highest charge? CuCl2 BaCl2 Na3PO4 Fe(NO3)3 Complete the table below. Formula Name CaCl2 Calcium Chloride Mg3(PO4)2 Magnesium phosphate Co(MnO4)2 Cobalt (II) permanganate Fe2S3 Iron (III) Sulfide H2SO3 Sulfurous acid HClO Hypochlorous acid P4O10 Tetraphosphorus decoxide N2O5 Dinitrogen pentoxide Atomic Theory & Nuclear Chemistry Complete the table below.
    [Show full text]
  • Agenda 10/6/2017 Per 2. Isotope - One More Time
    Agenda 10/6/2017 Per 2. Isotope - one more time https://drive.google.com/drive/folders/0BzGRyLjDEz_XdFJrN2ZBNkM4TDg • Slip Quiz • Modern Model of the Atom • Limitations of Model 1 in Isotopes Pogil • Average Atomic Mass • Looking for Patterns - Analysis Activity • Homework Slip Quiz 1.How many neutrons in an atom of neon-21 (21Ne). State clearly how you figure it out. 2. How many electrons in a neon-21 atom? How do you know? Slip Quiz 1.How many neutrons in an atom of neon-21 (21Ne). State how you know. I find neon’s atomic number on periodic table, neon has atomic number 10 which tells me it has 10 protons in its nucleus. The remainder of the particles in the nucleus are neutrons. Mass number - atomic number = number of neutrons 21 - 10 = 11 So Ne-21 has 11 neutrons. Slip Quiz 2. How many electrons in a neon-21 atom? How do you know? I know that for an electrically neutral atom, the number of protons in the nucleus is equal to the number of electrons in the electron cloud around the nucleus. For question 1 I found the atomic number of neon-21 is 10, hence the atoms have 10 protons and must also have 10 electrons. Isotopes Back to last Extension Questions 17. What characteristics of Model 1 are inconsistent with our understanding of what atoms look like? Note, limitations of models always exist, and we should be aware of them so we don’t try to use the model in situations where it does not really apply.
    [Show full text]
  • Average Or Apparent Mass of an Element SCIENTIFIC Isotopes and Atomic Mass
    Average or Apparent Mass of an Element SCIENTIFIC Isotopes and Atomic Mass Introduction At the beginning of the 19th century, John Dalton proposed his new atomic theory—all atoms of the same element are identical and equal in mass. It was a simple yet revolutionary theory. It was also not quite right. The discovery of radioactivity in the 20th century made it possible to study the actual structure and mass of atoms. Gradually, evidence was obtained that atoms of the same element could have different masses. These atoms were called isotopes. How are isotopes different from one another? What is the relationship between the atomic mass of an element and the mass of each isotope? Concepts • Isotope • Atomic and electron structure • Mass number • Atomic mass Materials Bags, zipper-lock, 15 Lima beans, 20 oz Balance, centigram (0.01-g precision) Navy beans, 4 oz Kidney beans, 12 oz Weighing dishes or small cups, 4 Labeling pen or marker Safety Precautions Although the materials used in this activity are considered nonhazardous, please observe all normal laboratory safety guidelines. The food- grade items that have been brought into the lab are considered laboratory chemicals and are for lab use only. Do not taste or ingest any materials in the chemistry laboratory. Wash hands thoroughly with soap and water before leaving the laboratory. Preparation “Bean bag” isotopes may be mixed in any proportion to prepare samples for analysis. The mixtures analyzed in the Sample Data section were prepared by mixing navy beans, kidney beans, and lima beans in the following proportion: 100 g navy beans, 280 g kidney beans, and 500 g lima beans (Note: 1 oz = 28.35 g).
    [Show full text]
  • Production of Aluminium and the Heavy Magnesium Isotopes in Asymptotic Giant Branch Stars
    CSIRO PUBLISHING www.publish.csiro.au/journals/pasa Publications of the Astronomical Society of Australia, 2003, 20, 279–293 Production of Aluminium and the Heavy Magnesium Isotopes in Asymptotic Giant Branch Stars A. I. Karakas and J. C. Lattanzio School of Mathematical Sciences, Monash University, Wellington Road, Clayton, Vic 3800, Australia [email protected] Received 2003 January 20, accepted 2003 May 30 Abstract: We investigate the production of aluminium and magnesium in asymptotic giant branch models covering a wide range in mass and composition. We evolve models from the pre-main sequence, through all intermediate stages, to near the end of the thermally-pulsing asymptotic giant branch phase. We then perform detailed nucleosynthesis calculations from which we determine the production of the magnesium and aluminium isotopes as a function of the stellar mass and composition. We present the stellar yields of sodium and the magnesium and aluminium isotopes. We discuss the abundance predictions from the stellar models in reference to abundance anomalies observed in globular cluster stars. Keywords: stars: AGB and post-AGB — stars: abundances — stars: interiors — stars: low mass — ISM: abundances 1 Introduction 1997; Siess, Livio, & Lattanzio 2002). There are currently In recent years our attempts to understand many aspects no quantitative studies of the production of the neutron- of nucleosynthesis and stellar evolution have come to rely rich Mg isotopes in low-metallicity WR stars. There are on our understanding of the production of the magne- quantitative studies of magnesium production in low- sium and aluminium isotopes. For example, abundance metallicityAGB stars (Forestini & Charbonnel 1997; Siess anomalies in globular cluster stars have been a problem et al.
    [Show full text]
  • Atomic Mass ƒ 4.6 – Electron Energy Levels Chapter 4 ƒ 4.7 – Electron Configurations ƒ 4.8 – Trends in Periodic Properties
    Lecture Presentation 4.1 – Elements and Symbols 4.2 – The Periodic Table 4.3 – The Atom 4.4 – Atomic Number and Mass Number 4.5 – Isotopes and Atomic Mass 4.6 – Electron Energy Levels Chapter 4 4.7 – Electron Configurations 4.8 – Trends in Periodic Properties General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Elements: are pure substances from which all other things are built. are listed on the periodic table. Goal : Given its name, write its correct symbol; from the symbol. Write the correct name. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Element names come from planets, mythological figures, Chemical symbols minerals, colors, geographic locations, and famous people. Carbon, C • represent the names of the elements. • consist of one to two letters and start with a capital letter. One-Letter Symbols Two-Letter Symbols C carbon Co cobalt N nitrogen Ca calcium F fluorine Al aluminum O oxygen Mg magnesium General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Karen C. Timberlake Write the correct chemical symbols for each of the following elements: A. iodine B. iron C. magnesium D. zinc E. nitrogen General, Organic, and Biological Chemistry: Structures of Life, 5/e © 2016 Pearson Education, Inc. Karen C. Timberlake Give the names of the elements with the following symbols: Mercury (Hg) Is a silvery, shiny element that is liquid at room A.
    [Show full text]
  • Melt Solidification and Late-Stage Evaporation in the Evolution of a FUN Inclusion from the Vigarano C3V Chondrite
    Gewfiimica ep Cosmodzimica Act@ Vol. 55, pp. 623437 Copyright Q 1991 Pergamon #es pk. Printed in U.S.A. Melt solidification and late-stage evaporation in the evolution of a FUN inclusion from the Vigarano C3V chondrite ANDREW M. DAVIS,’ GLENN J. MACPHERSON,~ ROBERT N. CLAYTON, 1*3*4TOSHIKO K. MAYEDA,’ PAUL J. SYLVESTER,~ LAWRENCE GROSSMAN,“~ RICHARD W. HINTON,*‘* and JOHN R. LAUGHLI~~ ‘Enrico Fermi Institute, University of Chicago, Chicago, IL 60637, USA *Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA 3Department of the Geophysical Sciences, University of Chicago, Chicago, IL 60637, USA “Department of Chemistry, University of Chicago, Chicago, IL 60637, USA (Received March 26, 1990; accepted in revisedform November 29, 1990) Abstract-Vigarano 1623-S is a forsterite-bearing refractory inclusion in which oxygen, magnesium, and silicon show large degrees of mass-dependent isotopic fractionation. The core of 16234 consists of forsteritic olivine, fassaite, melilite (Ak&, and spinel, all of which show isotopic mass fractionation, averaging -30.6L/amu for magnesium and - lO.OL/amu for silicon; it is enclosed in a mantle consisting of aluminous melilite (Ak 16-6o),spinel, perovskite, and hibonite. Hibonite and spine1 in the mantle are enriched in heavy isotopes of magnesium by S- 1%/amu relative to the core. 1623-5 originally formed by solidification of a magnesium-rich melt. The endemic isotopic mass fractionation may have been caused by evaporation of that melt or may reflect an earlier evaporation event affecting the reservoir from which the interior of 1623-5 formed. Later fiash remelting of the outer part of the core, and vola- tilization of SiO2 and MgO from the melt so produced, caused formation of a mantle that is in isotopic and petrologic di~uili~~um with the core.
    [Show full text]
  • TABLE of CONTENTS Radiation, Radioactivity, and Risk Assessment
    TABLE OF CONTENTS Radiation, Radioactivity, and Risk Assessment TABLE OF CONTENTS OVERVIEW — THE THREE “R’s”: RADIATION, RADIOACTIVITY, AND RISK ASSESSMENT (article) ...... 1 Table 1 — Radiation Doses ...................................................................................................................... 5 Table 2 — Comparing Radiation Risk to Other Risks ............................................................................... 5 Table 3 — Radioactivity of Some Natural and Man-Made Materials ........................................................ 6 Table 4 — Half-lives of Some Radioactive Isotopes and Their Uses ........................................................ 6 Table 5 — Units of Radiation and Radioactivity ........................................................................................ 7 INSTRUCTOR’S GUIDE ................................................................................................................................... 9 ACTIVITY 1 — LET’S INVESTIGATE ............................................................................................................... 15 ACTIVITY 2 — TIME LINE ................................................................................................................................ 19 ACTIVITY 3 — FINDING THE AGE OF A FOSSIL ........................................................................................... 25 ACTIVITY 4 — RADIOACTIVE GOLF BALL FINDER ..................................................................................... 29 ACTIVITY
    [Show full text]
  • Separation of Magnesium Isotopes by 1-Aza-12-Crown-4 Bonded Merrifield Peptide Resin
    Korean J. Chem. Eng., 18(5), 750-754 (2001) SHORT COMMUNICATION Separation of Magnesium Isotopes by 1-Aza-12-Crown-4 Bonded Merrifield Peptide Resin Dong Won Kim†, Byong Kwang Joen, Soo Han Kwon, Jae Sup Shin, Hai Il Ryu*, Jong Seung Kim** and Young Shin Joen*** Department of Chemistry, College of Natural Sciences, Chungbuk National University, Cheongju 361-763, Republic of Korea *Department of Chemistry Education, College of Education, Kongju National University, Kongju 314-701, Republic of Korea **Department of Chemistry, Konyang University, Nonsan 320-711, Republic of Korea ***Division of Chemical Analysis, Korea Atomic Energy Research Institute, Daejeon 305-606, Republic of Korea (Received 5 March 2001 • accepted 18 June 2001) Abstract− Magnesium isotope separation was investigated by chemical ion exchange with the 1-aza-12-crown-4 bonded Merrifield peptide resin using elution chromatography. The capacity of the novel azacrown ion exchanger was 1.0 meq/g dry resin. The heavier isotopes of magnesium were enriched in the resin phase, while the lighter isotopes were enriched in the solution phase. The single stage separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assays. The separation factors of 24Mg2+-25Mg2+, 24Mg2+-26Mg2+, and 25Mg2+-26Mg2+ isotope pairs were 1.012, 1.024, and 1.011, respectively. Key words: Monoazacrown, Capacity, Distribution Coefficient, Magnesium Isotope, Separation, Isotope Effect, Chromatog- raphy INTRODUCTION bert et al. [1961] also reported that the isotope enrichment of magne- sium, calcium, strontium, and barium through the migration of ions It was reported that crown ethers might also be applicable to the in molten halides.
    [Show full text]
  • CH1 1. State Whether the Following Properties of Matter Are Physical Or Chemical
    CH1 1. State whether the following properties of matter are physical or chemical. (a) An iron nail is attracted to a magnet. (b) A piece of paper spontaneously ignites when its temperature reaches 451 °F. (c) Abronze statue develops a green coating (patina) over time. (d) A block of wood floats on water. Ans: a. Physical b. Chemical c. Chemical d. Physical 2. Express each number in exponential notation. (a) 8950.; (b) 10,700.; (c) 0.0240; (d) 0.0047; (e) 938.3; (f) 275,482. Ans: a. 8.950 × 10 b. 1.0700 × 10 c. 2.40 × 10 d. 4.7 × 10 e. 9.383 × 10 f. 3 4 −2 −3 2 25482 × 10 5 3. Express each value in exponential form. Where appropriate, include units in your answer. (a) speed of sound (sea level): 34,000 centimeters per second (b) equatorial radius of Earth: 6378 kilometers (c) the distance between the two hydrogen atoms in the hydrogen molecule: 74 trillionths of a meter . × . × (d) = .ퟑ× ퟐ �ퟐ ퟐ ퟏퟎ �+�ퟒ ퟕ ퟏퟎ � −ퟑ ퟓ ퟖ ퟏퟎ Ans: a. 3.4 × 10 cm s b. 6.378 × 10 km c. 7.4 × 10 m d. 4.6 × 10 4 3 −11 5 ⁄ 4. Express each of the following to four significant figures. (a) 3984.6; (b) 422.04; (c) 186,000; (d) 33,900; (e) . × ; (f) . × . −ퟑ ퟑ Ans: a. 3985 b. 422.0 c. 1.860 × 10 d. 3.390 × ퟔ10ퟑퟐퟏ e. 6.ퟏퟎ321 × 10ퟓ ퟎퟒퟕퟐ f. 5.047ퟏퟎ× 10 5 4 −3 3 5. An American press release describing the 1986 nonstop, round-the-world trip by the ultra-lightweight aircraft Voyager included the following data: flight distance: 25,012 mi flight time: 9 days, 3 minutes, 44 seconds fuel capacity: nearly 9000 lb fuel remaining at end of flight: 14 gal To the maximum number of significant figures permitted ,calculate (a) the average speed of the aircraft in kilometers per hour (b) the fuel consumption in kilometers per kilogram of fuel (assume a density of for the fuel) Ans: a.
    [Show full text]
  • An Experimental Study of Magnesium-Isotope Fractionation in Chlorophyll-A Photosynthesis
    UC Davis UC Davis Previously Published Works Title An experimental study of magnesium-isotope fractionation in chlorophyll-a photosynthesis Permalink https://escholarship.org/uc/item/8x5346hj Journal Geochimica et Cosmochimica Acta, 70(16) ISSN 0016-7037 Authors Black, J R Yin, Q Z Casey, W H Publication Date 2006-08-01 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Geochim. Cosmochim Acta June 07,2006 An Experimental Study of Magnesium-Isotope Fractionation in Chlorophyll-a Photosynthesis Jay R. Black Department of Chemistry Department of Geology, University of California, Davis, CA 95616. [email protected] Qing-zhu Yin Department of Geology, University of California, Davis, CA 95616. [email protected] and William H. Casey* Department of Chemistry Department of Geology, University of California, Davis, CA 95616. [email protected] keywords: photosynthesis, magnesium isotopes, isotope fractionation, chlorophyll, cyanobacteria, biogeochemistry running title: Mg-isotope fractionation in chlorophyll-a 1 Abstract Measurements are presented of the magnesium isotopic composition of chlorophyll-a, extracted from cyanobacteria, relative to the isotopic composition of the culture medium in which the cyanobacteria were grown. Yields of 50-93% chlorophyll-a were achieved from the pigment extracts of Synechococcus elongatus, a unicellular cyanobacteria. This material was then digested using concentrated nitric acid to extract magnesium. Separation was accomplished using columns of cation-exchange
    [Show full text]
  • NGSS Lesson Planning STARS Elements Grade/Grade Band: HS Topic: Periodic Table: Properties and Symbols Lesson # Unit 1
    NGSS Lesson Planning STARS Elements Grade/Grade Band: HS Topic: Periodic Table: Properties and Symbols Lesson # Unit 1 Brief Lesson Description: Challenge students to discover repeating patterns and properties of the elements. Performance Expectation(s): HS-PS1-1. Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms. Specific Learning Outcomes: 1. Students will identify and describe the organization and components of the periodic table. 2. Students will determine relationships between chemical and physical properties of elemental families in the periodic table. 3. Students will manipulate protons, neutrons, and electrons to understand the composition and atomic symbols of each element on the periodic table. 4. Students will understand and apply the octet rule to create stable chemical compounds. Narrative / Background Information Prior Student Knowledge Familiarity with the Bohr model. Realization that the model of the atom is used to explain observable properties of elements and compounds. Physical changes. Elements, compounds, and mixtures. Remind students of the following background explanations during the Opening Activity: Both physical and chemical changes are occurring when a candle is lit. Candle wax is essentially a lot of carbon and hydrogen atoms bonded together as molecules called hydrocarbons. These atoms and molecules are vibrating, and they are attracted to one another as a solid. These attractions between the molecules are called intermolecular forces. When the solid wax is heated, the molecules move faster and faster, and the intermolecular forces begin to break. Eventually, the solid melts to form liquid wax.
    [Show full text]
  • RAD I at I on from MAGNESIUM26 UNDER PROTON BOMBARDMENT DISSERTATION Presented for 1B Partial Fulfillment Af the Requirem
    GAMMA- RAD I AT I ON FROM MAGNESIUM26 UNDER PROTON BOMBARDMENT DISSERTATION Presented 1b Partial Fulfillment af the Requirements for the Degree Doctor of Philosophy ir. the Graduate School of The Ohio State University By LEONARD NELSON RUS.iELL, B .A. The Ohio State University 1952 Approved by: Adviser 1 ACKN OWLEDGMENTS I wish to express my appreciation to Dr. John N. Cooper whose guidance helped in making this disser­ tation possible. I also wish to acknowledge the able assistance of Dr. J.C. Harris, Mr. Warren E. Taylor, and the other members of the Van de Graeff generator staff in carrying through the experimental work de­ scribed in the following pages. To my wife and me parents I extend full credit for their undying in­ spiration and faith throughout the course of my edu­ cation. soa<;62 - 1- GAMMA-RADIATION FROM MAGNESIUM26 UNDER PROTON BOMBARDMENT I . INTRODUCTION One of the experiments for which electrostatic generators are particularly well adapted is the study of proton capture reactions in light nuclei. Among the light elements magnesium remains as one In which proton capture reactions have not been investigated thoroughly. In the past the study of these reactions in magnesium has been confined to relatively low en­ ergies and has been complicated by the fact that there are three steble isotopes of magnesium, all relatively abundant in natural magnesium. The work done by other investigators in the low energy region indicated that there were resonances in the spectrum that originated in each of the three isotopes. These investigations are discussed in more detail in Section II of this paper.
    [Show full text]