2Overview Learn about the composition of matter Learn the difference between elements and compoundsLearn to distinguish between physical and chemical properties and changesLearn to distinguish between mixtures and pure substancesLearn to methods of separating mixtures
3Matter Can exist in three states – solid, liquid and gas Can be described in terms of its physical and chemical properties
4Figure 2.7: The three states of matter: Solid. Notice the molecules of a solid are very close together and are not moving fast.
5Figure 2.7: The three states of matter: Liquid The molecules of a liquid are further apart from each other and are moving faster than that of a solid.
6Figure 2.7: The three states of matter: Gas. Molecules of a gas are very far from each other and moving very fast.
10HomeworkRead Chapter 2Answer the Focus questions at the end of selected Sections (pages 29 & 41)
11Figure 2.18: The organization of matter. Matter is the big picture. It is divided up into 2 major parts mixture and pure substances. Mixtures may be separated by physical methods filtration, distillation, by sight. Compounds may be separated into its elemental parts by chemical methods electrolysis . Elements can not be separated by physical nor chemical methods. Nuclear reactions are the only way to break into elements.
12Elements and compounds Atoms – tiny particles that make up matterElements are made of atomsNo two elements are made of the same atomsMade of one type of atomCompounds are made of molecules that are made of two or more different atoms bonded togetherA specific compound consists of the same particles throughoutMolecules are made of atoms that are “stuck” together bonded. CO2Always have the same composition same combination of atoms.Elements are found on the Periodic Table of Elements. Compounds are not.No matter where you find a compound it is the same combination of elements whether it be here in Chattanooga or Russia.
13Top TenYou are responsible for this information in this orderfor your next test
14Figure 2.5: The three allotropes of the element carbon: Diamond. Notice the structure. Pressure of the earth and time has played an important role in this structure. The molecule looks like a diamond.
15Figure 2.5: The three allotropes of the element carbon: Graphite. Notice the structure. Layers of crystals.
16Figure 2.5: The three allotropes of the element carbon: Buckminsterfullerene. Notice the structure. It is a ring.
17CompoundsCarbon monoxide and carbon dioxide are both made of carbon and oxygen but in different combinations.Water and hydrogen perioxide are the same way.
18Oral Quiz Element or compound OxygenCarbonCarbon monoxideSugarnylonCopper wireSilver nitrateLeadSaltMagnesium strips
19Chemical propertiesDescribe a substance’s ability to undergo a change to a different substance
20Physical propertiesAre the characteristics a substance exhibits as long as no chemical change occurs.
21Physical changeInvolves a change in one or more physical properties, but no change in composition.The most common physical changes are changes of state:solid liquid gas
22Chemical changeTransforms a substance into a new substance or substancesInvolves a change in the fundamental components of the substanceA given substance changes into a different substance or substancesAre called reactionsEx. Silver tarnished by reacting with substances in the airEx. A plant form a leaf by combining various substances from the air and soil
23Figure 2.8: Electrolysis, the decomposition of water by an electric current, is a chemical process.
24Mixture Has variable composition Homogeneous mixture (solution) Has the same properties throughoutEx. tea, sugar water, glass, alloysHeterogeneous mixtureDoes not have the same properties throughoutEx. granite, salt & pepper, Italian dressing
31Figure 2.15: No chemical change occurs when salt water is distilled.
32Figure 2.14: The solution is boiled and steam is driven off.
33Figure 2.14: Salt remains after all water is boiled off.
34Pure substances Two types Elements Compounds Which cannot be broken down chemically into simpler substancesComposed of tiny particles called atoms.Each element has a characteristic type of atom.All elements are on the Periodic table of elementsCompoundsWhich can be broken down chemically into elementsAre composed of different types of atoms.Contain molecules particles that are composed of atoms bonded to one anotherEx. Sugar, gasoline, baking soda, plastics
36Mixtures quiz - Classify as Homogeneous/heterogeneous or pure substance A multivitamin tabletThe blue liquid in your car’s windshield washerA Spanish omeletA diamondGasolineA jar of jelly beansChunky peanut butterMargarine
37Classzone.com Go to classzone.com Click on science to find your book the state of Tennessee World of Chemistry Chapter 2Flip through the flashcardsTake Test 1 Bring results to class tomorrow.
39Physical and Chemical Changes Quiz Iron metal is melted.Wood burns in airA rock is broken into small pieces.Milk turns sour.Iron combines with oxygen to form rust.The inside of an apple turns brown when exposed to air.You make scrambled eggs.You step on a piece of chalk and it becomes powdered.You use a flashlight when the electricity goes out.Steam from hour hot shower condenses on a cold mirror.
40Physical or Chemical property Quiz The boiling point of a certain alcohol is C.A diamond is very hardSugar ferments to form alcohol.A gold wire can be flattened and used for foilGallium metal melts in your handPlatinum does not react with oxygen at room temperature.A dead tree gets chopped for firewood.The copper sheets that form the “skin” of the Statue of Liberty have acquired a greenish coating over the years.