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Bell Work: BW Composition Book. Practice: Symbols and Elements. Na K Cesium Strontium Be Mg Boron Calcium Lithium Barium H Rb Francium Ra Aluminum Ga Indium Tl. Answers: s ymbols and element …. Na - sodium K - potassium Cesium - C s Strontium - Sr Be - Beryllium
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Practice: Symbols and Elements • Na • K • Cesium • Strontium • Be • Mg • Boron • Calcium • Lithium • Barium • H • Rb • Francium • Ra • Aluminum • Ga • Indium • Tl
Answers: symbols and element…. • Na - sodium • K - potassium • Cesium - Cs • Strontium - Sr • Be - Beryllium • Mg - Magnesium • Boron - B • Calcium - Ca • Lithium - Li • Barium - Ba • H - Hydrogen • Rb - Rubidium • Francium - Fr • Ra - Radium • Aluminum - Al • Ga - Gallium • Indium - In • Tl - Thallium
Quiz Tomorrow • Know the elements and symbols for groups 1A, 2A and 3A • Spelling counts The Element Song
Matter • Anything that has mass and takes up space.
Matter Pure Substances Mixtures Homogenous – the mixture appears to be the same with uniform composition throughout It always has a single phase It is called a solution Heterogeneous – the mixture does not have uniform composition and the individual substances remain distinct • Elements - consist of the same types of atoms and cannot be broken down into simpler substances by chemical or physical means • Compounds – chemical combination of two or more different elements. It can be broken into simpler substances by chemical means and has properties different from its component elements
Homogenous vs HeterogeneousResource Homogeneous Solutions Heterogeneous Mixture Solid and liquid like oil and vinegar Mayonnaise: drops of oil and water can be seen in a microscope Fresh squeezed orange juice Pizza Granite Dirt Blood Milk • Dissolved substances like table salt in water • Kool-Aid or Tea • Alloys like bronze, which is a mixture of copper and tin • Air – nitrogen, oxygen, Argon and trace elements • Properties depend on concentrations or percent composition, which is not a set proportion
Ways to Separate Mixtures Evaporation Filtration Distillation Chromatography Crystallization Decant Centrifuge Magnetism
Pure Substances Let’s look at two elements
Today’s ElementNa Sodium • Periodic Table Placement • Group 1A or 1 • Period 3 Video: Sodium in water Video: Sodium and Chlorine react to create table salt Article about Bayou Corne, LA Sinkholes from Salt Domes NPR mp3 audio Video: Sink Hole activity August, 2013
Today’s ElementCl Chlorine • Periodic Table Placement • Group 7A or 17 • Period 3 Chlorine gas is poisonous. Chlorine is used as a cleaner and is used to sanitize swimming pools.
Compounds • Video of salt formation From Na and Cl Law of Definite Proportions The elements comprising compounds combine in definite proportions by mass. Examples NaCl, H2O, CO2, C6H12O6
Law of Multiple Proportions • Compounds made of the same elements can differ from each other. • Example: water H2O and peroxide H2O2 glucose C6H12O6 and sucrose C12H22O11 • By finding the percent composition of each element in a compound, one can determine if compounds comprised of the same elements are the same. Textbook page 76-77
Physical vs Chemical Properties Physical Properties Chemical Properties The ability or inability of a substance to combine with or change into one or more new substances. Examples: Ability to react with a substance, flammability, rusting, tarnishing A characteristic of matter that can be observed or measured without changing the sample’s composition Examples: density, color, taste, hardness, and melting point
Physical Properties of Matter Extensive Properties Intensive Properties Independent of the amount of the substance • Dependent upon the quantity of a substance
Physical vs Chemical Changes Physical Changes Chemical Changes Process involving one or more substances changing into new substances (change in composition) Examples: Reacting, burning, baking, rusting, tarnishing Evidence: Change in color or temperature Giving off gas (bubbles) Changes which alter the substance without changing its composition Examples: State of matter change size or shape change Dissolving or mixing with another substance Evidence: Change in state or shape, mixture
Dmitri MendeleevRussian ChemistCreated the Periodic Table • In 1869, Mendeleev classified the then known 56 elements on the basis of their physical and chemical properties in the increasing order of the atomic masses, in the form of a table. • Mendeleev had observed that properties of the elements orderly recur in a cyclic fashion. He found that the elements with similar properties recur at regular intervals when the elements are arranged in the order of their increasing atomic masses. • He concluded that 'the physical and chemical properties of the elements are periodic functions of their atomic masses'. This came to be known as the law of chemical periodicity. • Resource
Henry MoseleyBritish ChemistRearranged then Periodic Table • Henry Moseley (1887-1915) • A British chemist, Henry Moseley studied under Rutherford and brilliantly developed the application of X-ray spectra to study atomic structure. • Moseley's discoveries resulted in a more accurate positioning of elements in the Periodic Table by closer determination of atomic numbers. • Tragically for the development of science, Moseley was killed in action at Gallipoli in 1915 Resource
Practice - Nitrogen • Protons • Electrons • Neutrons • Period • Group or Family
Water: Separation by Electrolysis Video of Electrolysis: Water to Hydrogen and Oxygen
Atomic Mass of a Compound • H2O Try these • CO2 • C6H12O6 H2 1.01 x 2 = 2.02 O 16 x 1 = 16.00 Add totals 2.02 + 16.00 18.02 1.01 + 1.01 + 16 = 18.02
Practice – Finding Atomic Mass • CO2 C 12.01 x 1 = 12.01 O2 16 x 2 = 32.00 Add totals 12.01 + 32.00 44.01
Practice – Finding Atomic Mass • C6H12O6 C6 12.01 x 6 = 72.06 H12 1.01 x 12 = 12.12 O2 16 x 6 = 96.00 Add totals 72.06 12.12 +96.00 108.18
Percent Composition of Mass for Mixtures • A 6g mixture of sulfur and iron is separated using a magnet. Data Sulfur (S) Iron (Fe) 5g 1g • Calculate the percent composition of S and Fe.
Percent Composition of Mass for Mixtures • A 6g mixture of sulfur and iron is separated using a magnet. Data Sulfur (S) Iron (Fe) 5g 1g • Calculate the percent composition of S and Fe. Part / Whole x 100 = % composition Sulfur: 5g/6g x 100 = Iron : 1g/6g x 100 =
Percent Composition of Mass for Mixtures • A 6g mixture of sulfur and iron is separated using a magnet. Data Sulfur (S) Iron (Fe) 5g 1g • Calculate the percent composition of S and Fe. Part / Whole x 100 = % composition Sulfur: 5g/6g x 100 = 83.33% S Iron : 1g/6g x 100 = 16.66% Fe
Use Percent Composition to find the composition of a compound • Use the periodic table to find the compound’s percent composition of each element. • List the atomic weight of each element in the compound • Note how many of each type of atom is in the compound • Add it all up to get the atomic weight of the whole compound
Atomic Mass of a Compound • H2O Try these • CO2 • C6H12O6 H2 1.01 x 2 = 2.02 O 16 x 1 = 16.00 Add totals 2.02 + 16.00 18.02 1.01 + 1.01 + 16 = 18.02
Practice – Percent Composition H2O part / whole x 100 = % composition % composition of H % composition of O
Practice – Percent Composition CO2 part / whole x 100 = % composition % composition of C % composition of O
Practice – Percent Composition C6H12O6 part / whole x 100 = % composition % composition of C % composition of H % composition of O
Law of Conservation of Mass • Mass is neither created nor destroyed in any process. It is conserved. Mass reactants = Mass products 2H2O + electricity yields 2H2 + O2
Isotopes • The atomic weight found on the periodic table is based on the average weight of all the isotopes of the element • Isotope – atoms of the same element with the same number of protons but different numbers of neutrons • M&M activity
Reading Isotopes Mass number - the sum of the protons and neutrons
More isotopes Argon 36, Argon 37…
S.I.Units • http://2012books.lardbucket.org/books/general-chemistry-principles-patterns-and-applications-v1.0/section_05.html#averill_1.0-ch01_s09_s01_s02_t02
http://chemwiki.ucdavis.edu/Physical_Chemistry/Atomic_Theory/The_Mole_and_Avogadro's_Constanthttp://chemwiki.ucdavis.edu/Physical_Chemistry/Atomic_Theory/The_Mole_and_Avogadro's_Constant