Properties of Matter:



Hayley Irving | Executive Study NotesChemistry module 1Properties of Matter:Inquiry Question: How do the properties of substances help us to classify and separate them?Explore homogeneous mixtures and heterogeneous mixtures through practical investigations:Using separation techniques based on physical propertiesFiltration SolubilityDecantation DensityFractional Distillation Boiling PointChromatography SolubilityEvaporation Boiling PointSeparating Funnel Density and MiscibilitySieving SizeMagnetic Separation MagnetismCentrifusion MassCalculating percentage composition by weight of component elements and/or compoundsGravimetric analysis: (mass of a substance)/(total mass of mixture) X 100%Example: Sand, salt and water mixture of 100g. From filtration, sand weights 50g. From evaporation, salt weighs 32g therefore water weights 18g. Therefore, sand is 50%, salt is 32% and water is 18%. Investigate the nomenclature of inorganic substances using IUPAC naming conventionsMetal ions (cations): add ion to endExample: sodium ion for Na1+Non-metal ions (anions): remove end, add –ideExample: fluoride for F1-Ionic compounds: one cation + one anionExample: sodium chloride for NaClCovalent compounds: prefixes where mono is omitted for first elementMono, di, tri, buta, penta, hexa, hepta, octa, nona, deca…..Example: carbon dioxide for CO2Polyatomic ions:Positive ions: Ammonium – NH4+Hydronium – H3O+–ate ions:Sulfate – SO42-Chlorate – ClO32-Nitrate – NO3-Phosphate – PO43-–ite ions: Sulfite – SO32-Chlorite – NO2-Nitrite – NO2-Phosphite – PO33-Other: Cyanide – CN-Classify the elements based on their properties in the periodic table through their: Physical Properties: Metals are: Solid at RTP mainlyLustrousMalleable exc. BismuthDuctileSilver-coloured exc. Gold and CopperDense exc. AluminiumHigh MP/BP exc. MercuryGood conductors of heat and electricityNon-Metals are: Gases at RTP mainlyNon-malleableNon-ductileDull in colourNot denseLow MP/BPPoor conductors of heat and electricityMetalloids are: Combinations of metallic and non-metallic propertiesShinyNon-malleableSemi-conductors of heat and electricityChemical Properties: Periodic table arranged in proton/atomic number orderSize decreases along a period but increases down a groupGroups have similar reactivity due to valence electron numbersSchrodinger: 2n2 electrons per shellAtomic Structure and atomic massInquiry Question: Why are atoms of elements different from one another? Investigate the basic structure of stable and unstable isotopes by examining: Their position in the periodic tableValence electrons equal to group numberProtons equal to atomic numberNeutrons equal to (atomic mass – atomic number)The distribution of electrons, protons and neutrons in the atomProtons and neutrons are found in the nucleusProtons are positively chargedNeutrons have no chargeElectrons are found in orbit around the nucleusElectrons are negatively chargedRepresentation of the symbol, atomic number and mass numberExample: Carbon-12C is the atomic symbol12 is the mass number, equal to the number of protons and neutrons6 is the atomic number, equal to the number of protonsModel the atom’s discrete energy levels, including electronic configuration and spdf notationElectrons surround the nucleus in orbits containing fixed energy levelsThey are referred to as energy shellsAs long as electrons stay in their orbit, it does not lose or gain energyElectrons are placed into sub-shells which are of varying energy levelsExample: 1s2 where 1 is the shell number, s is the sub-shell type and 2 is the number of electrons in the sub-shellCalculate the relative atomic mass from isotopic compositionAtomic massx X abundanceX + atomic massy X abundancey …. = relative atomic massInvestigate the energy levels in atoms and ions through:Collecting primary data from flame tests using different ionic solutions of metalsWhen metal atoms are heated they give off characteristic coloursThis allows unknown samples can be identifiedExamples: Barium Yellow-Green, Lithium Crimson, Strontium Scarlet, Sodium Yellow, Copper Blue, Potassium LilacExamining spectral evidence for the Bohr model and introducing the Schrodinger modelBohr: Electrons move between energy levels by absorbing/emitting light energyEnergy levels per shell/orbitAs an electron falls to a lower energy shell, it emits light energyEqual to energy difference between two shellsCorresponds to a specific light energy and therefore a specific line in line spectrumSchrodinger: Quantum Mechanical ApproachAssumed electrons have wave-like propertiesShells contain separate energy levels of similar energy called subshellsOrder of energy subshells: 1s<2s<2p<3s<3p<4s<3d<4p<5s<4d….Investigate the properties of unstable isotopes using natural and human-made radioisotopes as examples including: Types of radiation:Alpha particles are helium nuclei emitted by radioisotopes that have too few neutrons to be stable low energy radiationBeta particles are electrons emitted when a neutron turns into a proton and electron moderate energy radiationGamma rays are electromagnetic radiation waves emitted when alpha or beta reactions leave a nucleus with too much energy high energy radiationTypes of balanced nuclear reactions: Naturally occurring Alpha + Gamma 23892U 23490Th +42He + YNaturally occurring Beta 146C 147N + 0-1eArtificial Beta 9942Mo 99m43Tc + 0-1ePeriodicityInquiry Question: Are there patterns in the properties of elements? Demonstrate, explain and predict the relationships in the observable trends in the physical and chemical properties of elements in periods and groups in the periodic table, including: State of matter at RTPMetals are solid exc. MercuryNon-metals are mainly gasesElectronic charge and atomic radiiAs each proton is added, electronic charge increases so atomic radius shrinksAs a new shell is added at a new period, atomic radius increases due to low electronic chargeFirst ionization energy and electronegativityIonization energy increases along a period and decreases down a group due to electronic charge shrinking/growingElectronegativity increases along a period and decreases down a group due to electronic charge growing/shrinkingReactivity with waterMetals increases down a group and decreases along a periodNon-metals decreases down a group and increases along a periodBondingInquiry Question: What binds atoms together in elements and compounds? Investigate the role of electronegativity in determining the ionic or covalent nature of bonds between atomsIonic has large difference in electronegativity One wants to lose electrons, other wants to gain an electronCation donates electron to anionCovalent has small difference in electronegativityBoth want to gain an electronShare electronsInvestigate the differences between ionic and covalent compounds through:Using nomenclature, valency and chemical formulaeExample: sodium sulphide (ionic)[Na]1+[ S ]2-[Na]1+Example: carbon dioxide (covalent)::O=C=O::Examining the spectrum of bonds between atoms with varying degrees of polarity with respect to their constituent elements’ positions on the periodic tableElectronegativity is key factorCovalent bonds with equal distribution of valence shells are non-polarUnequal distribution makes it polar as the charge will pull electrons towards more electronegative atomModelling the shapes of molecular substancesValence-shell electron-pair repulsion (VSEPR) theoryNegatively charged electron pairs repel each otherInvestigate elements that possess the physical property of allotropyMain Study: CarbonDiamondDoes not contain individual molecules but forms continuous 3D lattice structureNo weak intermolecular forces present only strong covalent bonds to give strengthConductive of heat and electricityGraphiteCovalent bonds between atoms in layersWeak dispersion forces between layersHard in one direction but slippery in anotherCovalent layerConductive. Investigate the different chemical structures of atoms and elements, including but not limited to: Ionic:No freely moving electrons presentIons present only as liquid/gas form3D latticeHigh MP/BP, brittle crystals show strong forcesElectrical conductivity as liquidNot malleableMetallic solidsFreely moving charged particlesHigh densitiesAttractive forces hard to breakHigh MP/BPGood conductorsMalleableCovalent networksContinuous 3D latticeHigh MP/BPVery hard due to fixed positionsStrong bondsCovalent molecularStrong covalent bonds but mainly intermolecular forcesLow MP/BPInsolubleNot conductiveExplore the similarities and differences between the nature of intermolecular and intramolecular bonds and the strength of the forces associated with each, in order to explain the: Physical properties of elements:Intramolecular bonds are bonds between each atom within a moleculeEXAMPLE: hydrogen bonding, dipole-dipole and covalent bonding of a water moleculeHydrogen bonding only occurs with H—O, H—F, and H—N Physical properties of compounds:Intermolecular bonds are bonds between multiple molecules (weak)EXAMPLE: Water to other water molecules – VSEPR Theory ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download