61. Chemistry Definitions A chemistry Dictionary. Actinides elements 90 to 103 (after actinium) Acyl Group Compoundderived from a formula, ORCH Alkali Metals Metals of Group IA (Na, K, Rb http://home.nas.net/~dbc/cic_hamilton/dictionary/a.html

Chemistry Dictionary Terminology "A" A B C D ... Z Absolute Entropy (of a substance) Absolute Zero Absorption Spectrum Spectrum associated with absorption of electromagnetic radiation by atoms (or other species) resulting from transitions from lower to higher energy states. Accuracy How closely a measured value agrees with the correct value. Acid A substance that produces H+(aq) ions in aqueous solution. Strong acids ionize completely or almost completely in dilute aqueous solution. Weak acids ionize only slightly. Acid Anhydride The oxide of a nonmetal that reacts with water to form an acid. Acid Anhydride Compound produced by dehydration of a carbonic acid; general formula is RCOCR Acidic Salt A salt containing an ionizable hydrogen atom; does not necessarily produce acidic solutions. Activation Energy Amount of energy that must be absorbed by reactants in their ground states to reach the transition state so that a reaction can occur. Active Metal Metal with low ionization energy that loses electrons readily to form cations. Activity (of a component of ideal mixture) A dimensionless quantity whose magnitude is: equal to molar concentration in an ideal solution; equal to partial pressure in an ideal gas mixture; and defined as 1 for pure solids or liquids.

62. The Periodic Table Of The Elements chemically similar and tend to form singly charged ions (K + Na of atom and ionsizes is thus another element in the geometry of chemistry and minerology http://www.friesian.com/atoms.htm

The Periodic Table of the Elements It is not difficult to find periodic tables of the chemical elements. What is provided here, however, is a table with information drawn from different sources that may not always be found together (though there is the massive Handbook of Chemistry and Physics , edited by Robert C. Weast and Melvin J. Astle, of which I have the 62nd edition, 1981-1982, CRC Press, Inc.). Thus, atomic isotopes, half-lives, and decay modes are largely taken from Subatomic Physics , by Hans Frauenfelder and Ernest M. Henley (Prentice-Hall, Inc. 1974). Cosmic abundance of elements is taken from the Realm of the Universe , by George O. Abell (Holt, Rinehart, and Winston, Inc. 1976Abell's catalogue of galaxy clusters has now enshrined his name to the far reaches of the universe). Some minerological information comes from An Introduction to Minerology for Geologists Manual of Minerology Many of the sources above may seem somewhat out of date, but they reflect the period when I was studying these matters, and when I was especially intrigued to supplement a chemical view of the elements with a picture of the variety of nuclear isotopes. This table is not intended, therefore, as a resource for chemistry, physics, or minerology students. It is a resource for philosophy of science, illustrating basic ideas and information, where the most up to date data and the provision of all chemically useful information is not necessary: Data for reflection and theory, not for application and experiment. Some commentary, color coding, and further footnotes will be added.

63. Chemistry : Chapter 1 : Classifying Matter of physical separation particular to chemistry include filtration gold is a homogeneousmixture; 24k gold is into sodium and chlorine (elements), but always http://www.wwnorton.com/chemistry/concepts/chapter1/ch1_1.htm

View the other Key Equations and Concepts in this chapter Classifying Matter A - Physical Versus Chemical Properties B - Heterogenous Mixture, Homogenous Mixture, Compound, or Element Metal, Nonmetal, or Metalloid A. Physical Versus Chemical Properties Chemical properties are characterized by a change in identity, whereas physical properties are not. Any property that can be seen or measured is probably a physical property. Any property that describes changes in the substance is a chemical property. Changes in physical state (liquid, solid, or gas) involve physical properties, not chemical ones. Water has different names, depending on its physical state (ice is solid water, steam is gaseous water), but it is still the same substance. Classify the following as physical or chemical properties of water. density = 1.00 g/mL makes hydrogen gas when combined with sodium metal is colorless is formed when wood is burned Solution: This is a physical property; density can be measured without changing a substance to anything else.

64. #1 Site For Learning Chemistry The reason for this is that the electronic configuration of H is 1s 1 , same asthe Group IA elements or the alkali elements such as Na, and K. The middle http://home.att.net/~cat6a/metals-I.htm

Metals and Non-Metals - Part I Keywords: Help There are about 90 elements, up to Uranium, that are found naturally. Another 20 elements, beyond Uranium, called trans-uranium elements, have been produced artificially in the laboratories by nuclear reactions. Two elements, Technetium (Tc) and Promethium (Pm) that occur below Uranium are unstable in nature. Elements can be classified by the physical and chemical properties that they display. We have discussed about classification of elements in earlier chapters. The chemical behavior of all elements depends on their electronic configurations. It is the electrons that take part in chemical reactions and therefore their interactions are the main factors that determine the outcome of a chemical reaction. The periodic table of elements has been made on the basis of electronic configuration of elements alone. Depending on the availability of “free” electrons, elements can be classified as metals and non-metals. Free electrons are unbound electrons, beyond closed shells. In metals, these unbound electrons are given off or donated during compound formation. In non-metals, there are no free electrons, instead there is a deficiency of electrons. While forming compounds, non-metals borrow electrons. Examples of metals are Sodium (Na), Potassium (K), Gold (Au). Examples of non-metals are Carbon (C ), Oxygen (O), Nitrogen (N), Chlorine (Cl).

65. #1 Site For Learning Chemistry In the alkali metal group, consider elements lithium (Li), sodium (Na) and potassium(K). All these elements are metals, they are highly reactive and they show http://home.att.net/~cat6a/class_elem-I.htm

Classification of Elements - Part I Keywords: Help In the early part of the 19 th century, many chemists noted that chemical properties of elements showed some similarities. The elements could be formed into groups. In 1817, Dobereiner showed that elements came in groups of three, now known as Dobereiner’s triads. In 1863, a 44 year old French geologist, A. E. Béguyer de Chancourtois created a list of the elements, arranged by increasing atomic weight. The list was wrapped around a cylinder so that several sets of similar elements lined up, creating the first geometric representation of the periodic law. In England, a 32 year old analytical chemist John A. R. Newlands was also wrapping the elements, noting that chemical groups repeated every eight elements. He named this the octave rule, and compared it to a musical scale. Chemists Dmitrii I. Mendeleev, a Russian, and German Lothar Meyer, were working independently in 1868 and 1869 on the arrangement of elements into seven columns, corresponding to various chemical and physical properties. Their tables were similar - Meyer's table was an accurate accounting of the known facts about each element, such as melting point and atomic volume. The table clearly showed the existence of periodic chemical families. What we will study in this chapte r Dobereiner’s triads 2. Newlands’ Law of octaves

66. Nuclear Chemistry When studying nucle ar chemistry, there is a typical All radioactive elements disintegrateaccording to their specific half N O , the rate of decay, k, and the http://www.shodor.org/unchem/advanced/nuc/

HOME Course Chapters Calculator Fundamentals Mathematics Review Basic Concepts Advanced Concepts ... Integration Techniques Section Tests Pre-test Post-test Useful Materials Glossary Online Calculators Redox Calculator Kinetics Arrhenius Calculator Thermodynamics Calculator Nuclear Decay Calculator ... Nomenclature Calculator Related Information Links Texas Instruments Calculators Casio Calculators Sharp Calculators Hewlett Packard Calculators ... Contact Webmaster Nuclear Chemistry Nuclear Chemistry deals with the nuclei of atoms breaking apart. Atoms are continually undergoing decay. When studying nucle ar chemistry, there is a typical format used to represent specific isotopes. Nuclear equations are typically written in the format shown below. There are 5 different types of radioactive decay. Alpha decay follows the form: Where A is the parent isotope (the atom being broken apart) B is the daughter isotope or the isotope formed. When an element is broken down in alpha decay it looses two neutrons and two (2) protons. This means that the name of the element will change as well, moving back two (2) places on the per iodic table. Alpha decay is is not very penetrating because the He atoms capture electrons before traveling very far. However it is very damaging because the alpha particles can knock atoms off of molecules .Alpha decay is the most common in elements with an atomic number greater than 83. Beta negative decay follows the form: The beta emission increases the atomic number by one (1) by adding one (1) proton. At the same time, one (1)

67. Wauu.DE: Science: Chemistry: Elements: Potassium and isotopes. http//www.chemicalelements.com/elements/k.html. It sElemental Potassium Basic physical and historical information. http://www.wauu.de/Science/Chemistry/Elements/Potassium/

Home Science Chemistry Elements : Potassium Search DMOZ-Verzeichnis: All Categories Categories Onlye Links: ChemGlobe: Potassium Electronic, thermal, and steric data along with basic information. http://www.vcs.ethz.ch/chemglobe/ptoe/_/19.html ChemicalElements.com: Potassium Basic information, atomic structure, and isotopes. http://www.chemicalelements.com/elements/k.html It's Elemental: Potassium Basic physical and historical information. http://education.jlab.org/itselemental/ele019.html LANL: Potassium Sources, uses, properties, and isotopes. http://pearl1.lanl.gov/periodic/elements/19.html Potassium Data tables and historic information. http://www.scescape.net/~woods/elements/potassium.html Radiochemistry of Potassium Full text of the monograph by William T. Mullins and G. W. Leddicotte (Oak Ridge National Laboratory, Oak Ridge, Tennessee). [PDF] http://lib-www.lanl.gov/cgi-bin/getfile?rc000016.pdf Visual Elements: Potassium Image, animation, source, uses, physical information, and key isotopes. http://www.chemsoc.org/viselements/pages/potassium.html © 1998- 2002 Ein Service von Wauu.de

68. Positive And Negative Ions K, +. have pure Neon (Argon, Krypton etc.) but it is not possible to make chemicalsby reacting these elements with other elements. Nobel chemistry prize winners http://www.purchon.com/chemistry/ions.htm

Positive and Negative Ions Gondar Design Chemistry Index Flash 5 animations for chemistry Back Next A simple understanding of positive and negative ions will help you to predict the chemical formulae of most acids, bases and salts. Some atoms e.g. Sodium atoms, Potassium atoms, Fluorine atoms can easily turn into ions by losing or gaining electrons. The most reactive elements do this very readily. Elements like Neon, Argon, Krypton, and Xenon are very unreactive: it is virtually impossible for their atoms to lose or gain electrons. This means that it is not possible to find Neon ions or Argon ions etc. Positive ions Negative ions Stick them together All atoms are composed of and equal number of protons (in the nucleus) and electrons (orbiting around the nucleus). Apart from Hydrogen atoms, all atoms also contain Neutrons in their nuclei. Neutrons have no electric charge. Protons have a positive electric charge: P and electrons have a negative electric charge: e This means that if an atom has equal numbers of protons and electrons it will have no overall charge. When an atom loses an electron it must have more protons than electrons so it will have an overall positive charge: these are all positive ions. You will find these elements in the first column of the periodic table, this is Group I. H Li Na K The elements in Group II also make positive ions, but instead of losing a single electron, their atoms lose 2 electrons when they turn into ions: you will find these metals in the second column of your periodic table so they are Group II.

69. Chemistry Elements Chemical Information Find additional information about chemistry elements at Access titles, abstractsand citations from top journals in organic and related chemistry. http://www.chemindustry.com/chemicals/search/C/chemistry_elements.asp

Chemical: Enter a chemical name, CAS Number, or molecular formula. Use * for partial names (i.e. chloro*) No items found, please enter another query Find additional information about chemistry elements at: Access titles, abstracts and citations from top journals in organic and related chemistry. There is over 750,000 articles in the Beilstein database, from over 140 journals! Click here. Chemical properties, names and structures NIST WebBook by the National Institute of Standards and Technology ChemIDplus by the National Library of Medicine (NLM) MatWeb by Automation Creations, Inc. ChemExper by ChemExper NCI Database by W. D. Ihlenfeldt, Computer Chemistry Center, Institute of Organic Chemistry, Univ. of Erlangen-Nuremberg, Germany SDBS (Spectral data) by the National Institute of Advanced Industrial Science and Technology Tsukuba, Ibaraki, Japan Merck ChemDat Sigma Aldrich Safety and toxicology data ToxNet by the National Library of Medicine (NLM) ChemFate by the Syracuse Research Corporation Vermont SIRI by the University of Vermont Cornell University Chemistry dictionary Acronyms Database by Indiana University, Chemistry library

70. Chemistry Chapter 4 chemistry. Matter. Electrons in the K shell have the least energy. Acompound is two or more elements joined together by chemical bonds. http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio 101/Bio 101

Home General Biology 1 General Biology 2 Human Biology ... Ecology (requires password) Chapter 4 - Chemistry Matter Matter occupies space and has weight. It can exist as a solid, liquid, or gas. It may be possible to break some kinds of matter down into other kinds of matter with different properties. For example, water (H O) can be broken down into hydrogen and oxygen. Hydrogen and oxygen in the above example cannot be broken down any further because they are elements Elements Elements cannot be broken down into substances with different properties. For example, water (H O) is not an element because it can be broken down into hydrogen (H) and oxygen (O). The smallest particle of an element is an atom Elements are substances made up of only one kind of atom. There are 92 naturally occurring elements. Matter is therefore composed of 92 different kinds of elements. The following elements make up 98% of the body weight of organisms: Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur, Phosphorus. Atoms Atoms are composed protons, neutrons, and electrons.

71. Chemistry Made Easy With Professor Schwartz chemistry Made Easy With Professor Schwartz. molar mass of these elements are locatedon the periodic table of elements. K = 39.0 **notice that Oxygen is mult. http://www.fordhamprep.com/gcurran/sho/sho/convert/mol8.htm

Chemistry Made Easy With Professor Schwartz Molarity Molarity Many Chemical reactions take place in a solution. Molarity is one of the most common methods of expressing the relationship between a dissolved substance and the solution its in. Molarity - The ratio between the moles dissolved in a substance and the volume of solution in cubic decimeters. The common equation for molarity is M = moles of solute dm of solution **Remember** Now by following my steps you should be able to solve these problems in about 1 minute, Tops! Follow these steps in the example. What is the molarity of a solution of KNO that contains 606g of KNO in 2.00 liters of solution? STEP 1 Find the molar mass of KNO The molar mass is the same as the atomic mass only in grams. The molar mass of these elements are located on the periodic table of elements. K = 39.0 **notice that Oxygen is mult. by three there for this must be done to all elements with exponents N = 14.0 O= 16 x 3 = 48 STEP 2 Add the masses together and then divide this into the mass given. This gives you your moles.

72. Lecture Help-Complete Tutorials If you are looking for the old version of the chemistry Drill and Practice Tutorialsusing (WP) are word problems and (DA) are Chapter 2, Atoms and elements. http://science.widener.edu/svb/tutorial/

Lecture Help Pages with Solutions These problems were developed by Prof. George Wiger ( gwiger@chemistry.csudh.edu ) at California State University, Dominguez Hills. They have been reorganized for use with "Chemistry and Chemical Reactivity" by Kotz and Treichel and are used here with his permission. If you are looking for the old version of the Chemistry Drill and Practice Tutorials using (WP) are word problems and (DA) are data analysis problems, these are still available but are no longer supported. Old Version Chapter 1, Matter and Measurement Significant Figures Exponents Scientific Notation Percentage ... Converting Temperatures Chapter 2, Atoms and Elements Protons,electrons and neutrons Elements,moles and mass Chapter 3, Molecules, Ions and Compounds Simple Naming Names-Stock Notation Names to formulas Calculating gfws ... Combustion Analysis Chapter 4, Chemcial Equations and Stoichiometry Balancing chemical equations Mass Relationships in Chemical Reactions Mole Relationships in Chemical Reactions General Relationships in Chemical Reactions ... Combustion Analysis Chapter 5, Reactions in Aqueous Solution Predicting Precipitation Identifying acids and bases pH, pOH, [H

73. Instructional Materials In Chemistry molecules, elements, compounds, classification of elements and the chemistry Select Science and then chemistry on their Education Science curricula in K12 http://www.cln.org/subjects/chemistry_inst.html

Instructional Materials in Chemistry The WWW sites linked to from this page provide practical assistance for Chemistry teachers wanting to use the Internet as part of their classroom planning/instruction. Please read our 1995 Dow/NSTA Summer Workshop Lesson Plans Junior and senior high chemistry lesson plans developed by teachers in annual projects starting in 1995. Amazing Science at the Roxy: Teaching Resource Center AskERIC Lesson Plans - Science: Physical Science Over 50 lesson plans organized alphabetically and covering various grade ranges in K-12. Bizarre Stuff You Can Make In Your Kitchen This site is an ever growing warehouse of the kinds of projects some of the more demented of us tried as young people, collecting in one place many of the classic, simple science projects that have become part of the collective lore of amateur science. It is a sort of warped semi-scientific cookbook of tricks, gimmicks, and pointless experimentation, concoctions, and devices, using, for the most part, things found around the house. These are the classics. Strange goo, radios made from rusty razor blades, crystal gardens... amateur mad scientist stuff. If you happen to learn something in the process, consider yourself a better person for it. Bridge: Chemistry Links to about 10 sites that provide lesson plans, activities, or curricular units that explore hydrology from a chemical perspective.

74. Technetium Elements Chemistry Gmelin Handbook of Inorganic and Organometallic chemistry 8th Edition ElementTC Tc. Technetium ( Kugler, Hans K. Learn about Gmelin Handbook of Inorganic http://chemistry.designerz.com/chemistry-elements-technetium.php

Map.Designerz.com Science.Designerz.com Chemistry News Chemistry Chat ... Nobel Prize in Chemistry Channels Visited: Clear Featured Links Web Hosting Sign up for our mailing list Statistics: Chemistry Chemistry Elements Technetium Chemistry A comprehensive resource on Chemistry Elements Technetium Show Chemistry (Chemistry Elements Technetium) content on your web site Reach Chemistry (Chemistry Elements Technetium) Audience Save on Chemistry Elements Technetium books, magazines and software See which Chemistry Elements Technetium domain names are available Search Chemistry Elements Technetium on other search engines Press Releases, Stories and Articles on Chemistry Elements Technetium View all press releases Submit your press release View all articles Submit your article Featured Results (opens in a new window) Technetium Data tables and historic information. Rate Technetium It's Elemental: Technetium Basic physical and historical information. Rate It's Elemental: Technetium Visual Elements: Technetium Image, general and physical information, source, uses, key isotopes, and ionisation energies.

75. Actinium Elements Chemistry Gmelin Handbook of Inorganic and Organometallic chemistry 8th Edition ElementAC AC. Actinium (Sy Kugler, Hans K. Learn about Gmelin Handbook of Inorganic http://chemistry.designerz.com/chemistry-elements-actinium.php

Map.Designerz.com Science.Designerz.com Chemistry News Chemistry Chat ... Nobel Prize in Chemistry Channels Visited: Clear Featured Links Web Hosting Sign up for our mailing list Statistics: Chemistry Chemistry Elements Actinium Chemistry A comprehensive resource on Chemistry Elements Actinium Show Chemistry (Chemistry Elements Actinium) content on your web site Reach Chemistry (Chemistry Elements Actinium) Audience Save on Chemistry Elements Actinium books, magazines and software See which Chemistry Elements Actinium domain names are available Search Chemistry Elements Actinium on other search engines Press Releases, Stories and Articles on Chemistry Elements Actinium View all press releases Submit your press release View all articles Submit your article Featured Results (opens in a new window) It's Elemental: Actinium Basic physical and historical information. Rate It's Elemental: Actinium ChemGlobe: Actinium Electronic, thermal, and steric data along with an isotope table. Rate ChemGlobe: Actinium Wikipedia: Actinium Details the properties of the element, including its history, applications, and charateristics.

76. Free Full-Text Journals In Chemistry - L Survey Articles (1995-1998) PDF Review articles for d-elements from Coordinationchemistry Reviews and chemistry of the elements, Butterworth Heinemann http://www.chemistry.bsu.by/abc/current/fulltext04.htm

77. ANALYTICAL CHEMISTRY - ELEMENTS OF ELECTOCHEMISTRY ANALYTICAL chemistry LECTURE OUTLINE elements OF ELECTROchemistry. for studentstaking Analytical chemistry with Dr 1. Determinations of K eq and oxidation http://falcon.sbuniv.edu/~ggray/CHE3345/chp16.html

Back to ANALYTICAL CHEMISTRY Menu ANALYTICAL CHEMISTRY LECTURE OUTLINE: ELEMENTS OF ELECTROCHEMISTRY Lecture outline for students taking Analytical Chemistry with Dr. Gray at Southwest Baptist University. It is suggested that students print this out and use it for taking lecture notes during class. I. Introduction A. A number of analytical techniques are based upon oxidation-reduction reactions. B. Examples of these techniques would include... 1. Determinations of K eq and oxidation-reduction midpoint potentials. 2. Determination of analytes by oxidation-reductions titrations. 3. Ion-specific electrodes (e.g., pH electrodes, etc.) 4. Gas-sensing probes. 5. Electrogravimetric analysis: oxidizing or reducing analytes to a known product and weighing the amount produced 6. Coulometric analysis: measuring the quantity of electrons required to reduce/oxidize an analyte II. Terminology A. Reduction: the gaining of electrons B. Oxidation: the loss of electrons C. Reducing agent (reductant): species that donates electrons to reduce another reagent. (The reducing agent get oxidized.) D. Oxidizing agent (oxidant): species that accepts electrons to oxidize another species. (The oxidizing agent gets reduced.)

78. Periodic Table -- From Eric Weisstein's World Of Chemistry Puddephatt, R. J. and Monaghan, P K. The Periodic Table of the elements, 2nded. Oxford Oxford University Press, 1986. Royal Society of chemistry. http://scienceworld.wolfram.com/chemistry/PeriodicTable.html

Chemistry Contributors Romero Inorganic Chemistry Chemical Elements Periodic Table This entry contributed by Dana Romero The periodic table displays all chemical Elements systematically in order of increasing atomic number i.e., the number of protons in the nucleus In 1869, Russian chemist Dmitri Mendeleev first described an arrangement of the chemical elements now known as the periodic table. Mendeleev wrote, "The elements, if arranged according to their atomic weights, show a distinct periodicity of their properties.... Elements exhibiting similarities in their chemical behavior have atomic weights which are approximately equal (as in the case of Pt, Ir, Os) or they possess atomic weights which increase in a uniform manner (as in the case of K, Rb, Cs)." isotopes of an element have the same number of protons but a different number of neutrons They are chemically very similar but have a different atomic masses Atom Atomic Mass Atomic Number ... Nuclide References Atkins, P. W. The Periodic Kingdom: A Journey into the Land of Chemical Elements. New York: BasicBooks, 1997. Chang, J. "Table of the Nuclides."

79. 2.8 Case Study Computational Chemistry Fundamental to several methods used in quantum chemistry is the need to and the Irepresent integrals that are computed using elements i , j , k , and l of a http://www-unix.mcs.anl.gov/dbpp/text/node22.html

Next: 2.9 Summary Up: 2 Designing Parallel Algorithms Previous: 2.7 Case Study: Floorplan Optimization 2.8 Case Study: Computational Chemistry Our third case study, like the first, is from computational science. It is an example of an application that accesses a distributed data structure in an asynchronous fashion and that is amenable to a functional decomposition. 2.8.1 Chemistry Background Computational techniques are being used increasingly as an alternative to experiment in chemistry. In what is called ab initio quantum chemistry Plate 6 shows a molecular model for the active site region in the enzyme malate dehydrogenase, a key enzyme in the conversion of glucose to the high-energy molecule ATP. This image is taken from a simulation of the transfer of a hydride anion from the substrate, malate, to a cofactor, nicotinamide adenine diphosphate. The two isosurfaces colored blue and brown represent lower and higher electron densities, respectively, calculated by using a combined quantum and classical mechanics methodology. The green, red, blue, and white balls are carbon, oxygen, nitrogen, and hydrogen atoms, respectively. Fundamental to several methods used in quantum chemistry is the need to compute what is called the Fock matrix , a two-dimensional array representing the electronic structure of an atom or molecule. This matrix, which is represented here as

80. Salt, Multi-disciplinary Curriculum For High School Students: Chemistry Unit 2 chemistry. L2s 2 2p 6 M3s 2 3p 5 ) . Note K, L, and M and discuss themarkedly different properties of NaCl as compared to its individual elements. http://www.saltinstitute.org/42f.html

Salt: The Essence of Life Multidisciplinary Curriculum for Students Unit 2: Chemistry The Nature of Salt 1½ - 2 Class Periods Overview In this module students will identify the physical and chemical properties of salt. Background Chemically, salt consists of two elements, sodium (Na) and chlorine (Cl). Elemental chlorine is the chlorine atom (Cl), which pairs to form chlorine gas (Cl2). Neither element separately occurs free in nature, but each is found in abundance as the useful compound, sodium chloride (NaCl), or salt. It occurs naturally in many parts of the world as the mineral halite and as mixed evaporites in salt lakes. Seawater contains an average of 2.6% (by weight) NaCl, or 26 million metric tons per cubic kilometer (120 million short tons per cubic mile), an inexhaustible supply. Sodium chloride in solution consists of a positively charged sodium ion and a negatively charged chloride ion. In solid form the atoms arrange themselves in a cubic crystal lattice. Table salt, when viewed under a magnifying glass, can be seen to consist of tiny cube flakes. Salt varies in color from colorless, when pure, to white, gray or brownish, typical of rock salt (halite). Chemically, it is 60.66% chlorine (Cl) and 39.34% sodium (Na). The atomic weight of chlorine is 35.4527 and that of sodium is 22.989768. Getting Ready Time: 1 1/2 to 2 class periods Materials Per Student Group: 1/2 cup table salt, magnifying glass

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