Groups to know!Group 1: Alkali metalsHydrogen; not technically an alkali metalGroup 2: Alkaline Earth MetalsGroup 17 HalogensGroup 18: Noble gasesBroad categories of elementsMetals (left side and bottom of table)Shiny solids; conduct heat and electricity; are malleable and ductileNonmetals (right side and top of table)Solids (brittle), liquids and gases; nonconductorsMetalloids (between metals/nonmetals)Shiny solids (like metals); brittle (like nonmetals); semiconductorsMain group elements (representative elements)First two columns, last six (1A, 2A, 3A (13), 4A (14), 5A (15), 6A (16), 7A (17), 8A (18))Transition metalsMiddle ten columnsAverage atomic massAverage atomic massWeighted average of masses of all isotopes of an elementCalculated by multiplying the natural abundance of each isotope by its mass in amu and then summing these productsNatural abundanceProportion of a particular isotope, usually expressed as a percentage, relative to all the isotopes for that element in a natural sampleWeighted averageNeon is found in three isotopes in natureIsotope Neon-20, Neon-21, Neon-22Mass (amu) – 19.9924, 20.9940, 21.9914Natural abundance %- 90.4838, 0.2696 9.2465Average atomic mass of neon(19.9924x 90.4838) + (20.9940 x 0.2696) + (21.9914 X 9.2465) = 20.1797 amu2.5- The Mole1 mole of common substancesSymbol for Avogadro’s number Na = 6.02241x1023A mole is a unit for a specific numberA mole is Avogadro’s number of atoms in exactly 12 grams of carbon-12Convenient unit for expressing macroscopic quantities (atoms or molecules) involved in macroscopic processes we observeMoles as Conversion FactorTo convert btw number of particles and an equivalent number of molesMolar Mass- the mass (in grams) equal to the mass of an individual atom or molecule (in amu)The mass (in grams) of one mole of the substance (atom, molecule or formula unit)The molar mass (M) of HeMolecular mass/formula massMolecular massMass of one molecule of a molecular compoundSum of the atomic masses of the atoms in that compoundEx for one molecule of co2Co2 = c + 2o= 12.01 amu +92(16.00amu)= 44.01 amu/moleculeFormula mass: mass in atomic mass units of one formula unit of an ionic compoundMoles, mass, ad particlesNeed to know how to calculate betweenCHEM 111 1nd Edition Lecture 5 Outline of Last Lecture I. Significant Figures in Math OperationsII. Precision and AccuracyIII. Changing Units: Conversion Factorsa. Temperature ScalesIV. Chapter 2 (Electrons)a. Radioactivityb. The Nuclear Atomc. Atomic Mass UnitsOutline of Current Lecture II. Symbols of NuclidesIII. Periodic TableIV. The Molea. Moles as Conversion Factors b. Molecular mass/ formula massCurrent LectureIsotopes: atoms of an element containing the same # of protons but different # of neutronsNuclide: a specific isotope of an elementSymbols of NuclidesAtomic mass (A)= total number of “nucleons” (protons, neutrons) in the nucleusElemental Symbol = a one- or two-letter symbol to identify the type of atomAtomic number (Z)= the number of protons in the nucleus; determines the identity of the elementMendeleev’s Periodic Tableo He was not the first to come up with arranging elementso Ordered elements by atomic massThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Credited with it b/c he came up with the idea that there are probably chemical elementsundiscovered. He left holes in his table. Modern Periodic TableHorizontal rows: periods (1-7)Vertical Columns: contain elements of the same family or group (1-18)Groups to know!Group 1: Alkali metalso Hydrogen; not technically an alkali metalGroup 2: Alkaline Earth MetalsGroup 17 HalogensGroup 18: Noble gasesBroad categories of elements Metals (left side and bottom of table)- Shiny solids; conduct heat and electricity; are malleable and ductile Nonmetals (right side and top of table)- Solids (brittle), liquids and gases; nonconductors Metalloids (between metals/nonmetals)- Shiny solids (like metals); brittle (like nonmetals); semiconductors Main group elements (representative elements)- First two columns, last six (1A, 2A, 3A (13), 4A (14), 5A (15), 6A (16), 7A (17), 8A (18)) Transition metals- Middle ten columns  Average atomic mass- Average atomic masso Weighted average of masses of all isotopes of an elemento Calculated by multiplying the natural abundance of each isotope by its mass in amu and then summing these products- Natural abundanceo Proportion of a particular isotope, usually expressed as a percentage, relative to all the isotopes for that element in a natural sampleWeighted average- Neon is found in three isotopes in nature- Isotope Neon-20, Neon-21, Neon-22- Mass (amu) – 19.9924, 20.9940, 21.9914- Natural abundance %- 90.4838, 0.2696 9.2465- Average atomic mass of neon - (19.9924x 90.4838) + (20.9940 x 0.2696) + (21.9914 X 9.2465) = 20.1797 amu 2.5- The Mole 1 mole of common substances  Symbol for Avogadro’s number Na = 6.02241x1023- A mole is a unit for a specific number- A mole is Avogadro’s number of atoms in exactly 12 grams of carbon-12- Convenient unit for expressing macroscopic quantities (atoms or molecules) involved in macroscopic processes we observeMoles as Conversion Factor- To convert btw number of particles and an equivalent number of molesMolar Mass- the mass (in grams) equal to the mass of an individual atom or molecule (in amu)- The mass (in grams) of one mole of the substance (atom, molecule or formula unit)- The molar mass (M) of HeMolecular mass/formula mass- Molecular masso Mass of one molecule of a molecular compound o Sum of the atomic masses of the atoms in that compoundo Ex for one molecule of co2o Co2 = c + 2oo = 12.01 amu +92(16.00amu)o = 44.01 amu/molecule- Formula mass: mass in atomic mass units of one formula unit of an ionic compound- Moles, mass, ad particles-- Need to know how to calculate