Presentation on theme: "What is Matter? CP Chemistry notes Mixtures vs. Pure Substances"— Presentation transcript:
1 What is Matter? CP Chemistry notes Mixtures vs. Pure Substances Physical vs. Chemical PropertiesPhysical vs. Chemical ChangesCP Chemistry notes
2 What is Matter? Matter is anything that has mass and takes up space anything you can touch and feelmass is simply a measurement of the quantity of matter – how much there isit’s not the same as weight – it’s independent of gravity“space” is just a measurement of volumeall matter is made of tiny, tiny particlestypically separated into these classifications:pure substances: elements & compoundsmixtures: homogeneous & heterogeneousEnergy is NOT made of matter!
3 Matter: Classifications of Matter Pure SubstancesElementsCompoundsMixturesHomogeneous MixturesHeterogeneous Mixtures
4 Pure Substances forms of matter with definite or constant composition ElementsExamples of elementssimplest form of matteronly made of one kind of atomcannot be separated into simpler substanceseverything listed on the periodic table is an element!83 naturally occurring, 117 totalsome created by scientists, most recently in 2002helium [He]carbon [C]neon [Ne]sodium [Na]aluminum [Al]sulfur [S]iron [Fe]gold [Au]...etc!
5 Pure Substances - continued forms of matter with definite or constant composition CompoundsExamples of Compoundschemical combination of two or more kinds of atomcannot be separated into simpler substances by physical changesCAN be separated by chemical changesseparation results in new substances with different propertiespermanent changecombined by chemical bondsmolecules & ionic compoundsdistilled water [H2O]oxygen gas [O2]table salt [NaCl]sugar (sucrose) [C12H22O11]iron oxide (rust) [Fe3O4]sulfuric acid [H2SO4]sodium hydroxide (lye) [NaOH]...and many, many more!
6 Mixtures physical blends of two or more substances in which the substances retain their identity Homogeneous MixturesExamplesconsistent composition throughoutcan be separated through chemical and physical changesmore difficult to separate through physical changessome separation processes are distillation, freezing, coagulation, chromatographyhomogeneous mixtures in water are called solutionssolute is dissolved in solventsugar dissolved in watersalt dissolved in waterjust about any beverage except for distilled water, including carbonated beverageshomogenized milkbrasssteelmany plastics...and many, many more!
7 Heterogeneous Mixtures Mixtures - continued physical blends of two or more substances in which the substances retain their identityHeterogeneous MixturesExamplesinconsistent composition throughoutNOT evenly blendedrelatively easy to separate, especially through physical changesfiltration, sifting, magnetism, dissolvingtypes of heterogeneous mixtures:suspensions – particles will settle outcolloids – particles will NOT settle outairalmost all food!salad, cereal, trail mix, etc.bloodsoil/dirtcementwoodgranite...and many, many, more!
8 Classification flow chart follow the arrows to classify a sample of matter uniform properties?If not, it’s a heterogeneous mixturefixed composition?If not, it’s a homogeneous mixturecan be broken down chemically?If not, it’s an elementIf so, it’s a compound
9 Physical vs. Chemical Properties used to describe matter Physical PropertiesChemical Propertiescan be observed without changing the substancechanges in physical properties can be the result of physical change (can be reversed) or chemical change (CANNOT be reversed)examples are:size, shape, mass/weight, color, texture, density, melting/freezing point, boiling point, pressure (for gases)can only be observed through a permanent chemical change in the substanceused to predict chemical changes and classify substanceselements in the same column (group) on the periodic table have similar chemical propertieselements become less metallic and more nonmetallic as you go from left to right on the periodic table
10 Physical vs. Chemical Changes remember, chemistry is the study of matter and the changes it undergoes!Physical ChangeChemical Changechange in one or more physical properties of a substancecan be reversed - NOT permanentsame substance - does NOT change the chemical compositionexamples are:folding, compressing/expanding, cutting, dissolving, changes of state (boiling, melting, freezing, etc.)change in one or more chemical properties of a substanceCANNOT be reversed without another chemical change – permanent!new substance is formed, usually with some new physical properties as wellLaw of Conservation of Matter must ALWAYS be satisfied: “Matter cannot be created or destroyed, only changed”examples: burning, rusting, decomposition, digestion
11 Homework Quiz on Friday! Read Chapter , 3.4do these book problems:p.31 #1, 2, 4p.35 #7-12p.40 #14-18p.47 #24-28p.72 #25-28p.31 #3p.43 #19-20p #29, 34-35, 43, 46do Physical & Chemical Changes WS