3 What you will learn……. How to define substances and mixtures How to identify elements and compoundsHow to compare and contrast solutions, colloids and suspensions.This is important because you can form a better picture of your world when you understand the concepts of elements and compounds.
4 Teks ObjectiveIPC (7) The student knows relationships exist between properties of matter and its components. The student is expected to:7e:classify samples of matter from everyday life as being elements, compounds, or mixtures.
5 REMEMBER….. Matter Matter- anything that takes up space and has mass. Pure SubstancesMixtures
6 What are pure substances? have a definite compositioncan be elements or compounds.MatterPure SubstancesElementsCompounds
7 Pure Substance: ELEMENTS Are pure substances which CAN NOT be broken down through physical or chemical means.Composed of only one kind of atom- all atoms are the same.You can find all the known elements on the Periodic Table of Elements.
8 Pure Substance: ELEMENTS Examples of Elements:gold, silver, carbon, and hydrogenGOLD- AuSILVER- AgALL ATOMS ARE THE SAME!!!
9 Pure Substances: COMPOUNDS A compound is a pure substance composed of 2 or more elements that are chemically combined in definite proportions.Compounds DO NOT look or act like the elements that make them up.SALT- Sodium Chloride: (NaCl)Chlorine (Cl)- Green GasSodium (Na)- MetalWATER- H2O
10 Question?How are elements and compounds related?
11 Answer…….Compound contains 2 or more different elements
12 What are mixtures? Matter MIXTURES composed of 2 or more different substances that can be separated through physical meanscan be homogeneous or heterogeneousMatterMixturesHomogeneousHeterogeneous
13 HOMOGENEOUS MIXTURES The composition is the same throughout Homogeneous mixtures are solutions, so the particles are so small that they CAN NOT be seen through a microscopeLight passes through undisturbedExamples: coke, alcohol, iron, pure air, vinegarVinegarCoke
16 HETEROGENOUS MIXTURES MatterThe composition is NOT the same throughoutExamples: salad, soil, gelatinComponents can be observed.Can be classified as colloids or suspensionsMixturesHomogeneousHeterogeneousSolutionsColloids, Suspensions
17 HETEROGENEOUS MIXTURES: COLLOIDS Particles are not large enough to settle.Can be identified by using the Tyndall EffectShampooGelatin
18 Tyndall Effect- Detecting Colloids Scattering of light beam as it passes through a colloid.
19 Tyndall Effect- Detecting Colloids The light from the headlights is scattered by fog.The same colloid allows you to see the sunlight as it streams through the trees.
20 HETEROGENEOUS MIXTURES: SUSPENSIONS A liquid in which visible particles SETTLE.Muddy Water - Some mud particles will fall to the bottom and the water clears.Orange Juice - Has to be shaken before drinking because
21 SUMMARY Matter Mixtures Pure Substances Heterogeneous Homogeneous ElementsCompoundsSolutionsColloids, Suspensions
23 Section 2: Properties of Matter Teks 8A: distinguish between physical and chemical changes8C : investigate and identify the law of conservation of mass
24 You will learn……. How to identify substances using physical properties How to compare and contrast physical and chemical changeHow to determine how the law of conservation of mass applies to chemical changesThis is important because understanding the chemical and physical properties can help you use materials properly.
25 Physical PropertiesCharacteristics which can be observed without changing the chemical composition of the substance
26 Example - Physical Properties AppearanceSizeTextureShapeColorState of matter
27 Example - Physical Properties Behaviormagneticcan be drawn out into wires (copper)pounded into sheets (gold)ability to flowSmell (odor)densitymelting point, boiling point, freezing point
28 Physical ChangeChange the appearance or state of a substance but NOT it's chemical make-upThe identity remains the sameExamples: evaporation of water, melting of wax, dissolving of salt in water, breaking of glass
29 Question?Does a change in state mean that a new substance has formed? Explain
30 Answer……No the identity of the element or compound remains the same
31 Chemical PropertiesAre characteristics which depend upon the reaction with other materials.Examples: flammability, ability to rust, ability to react with water
32 Chemical ChangesProduce new substances that differ in appearance and make-up from the original substanceA change of one substance to another is a chemical changeExamples: burning, rusting , combustion, rotting, digestionRustingBurningCombustion
33 INDICATIONS THAT A CHEMICAL CHANGE MAY HAVE OCCURRED. -production of a gas-permanent color change-formation of bubbles or solids in a liquid-production of heat and lightColor ChangeGasPrecipitate
34 Weathering of Rocks by water Physical or Chemical?
35 Answer……Weathering can involve both physical and chemical change!