Presentation on theme: "Elements, Compounds, and Mixtures"— Presentation transcript:
1Elements, Compounds, and Mixtures 8th Grade Science8.P.1.1 Classify matter as elements, compounds, or mixtures based on how the atoms are packed together in arrangements.
2Essential QuestionsHow does the arrangement of atoms affect the classification of matter?What is the difference between elements, compounds, and mixtures?
3How do we classify matter? What is an element?A pure substance that is made up of only one kind of atom H, He, O2Organized on the periodic tableRepresented with a chemical symbolWhat is a compound?A pure substance made up of two or more elements that have been chemically combinedRepresented using a chemical formula C6H12O6, NaClWhat is a pure substance?Any substance that cannot be physically broken down into simpler substancesIncludes both elements and compounds
4What are mixtures? The physical combination of 2 or more substances Mixtures are NOT chemically combinedMixtures can be separated by physical means (filtration, evaporation, distillation)Mixtures are divided into two groupsHeterogeneousA mixture that is unevenly distributedHomogeneousA mixture that is evenly distributed
5Comparing Elements, compounds, and mixtures Creating a foldable:Fold a blank sheet of paper in half hamburger styleNext, fold the half size into thirdsCarefully cut along the folds of only the top half of folded paper so that you have 3 flaps, then glue down in your notebook
6Label each flap with the following information: ElementsCompoundsMixturesA pure substanceIn an element, all atoms are identical and share the same physical and chemical propertiesRepresented with a chemical symbolA compound is a combination of 2 or more elements joined by chemical bondsRepresented with a chemical formulaA combination of pure substancesA mixture is composed of element(s) and/or compound(s)Label each flap with the following information:Flap 1 Title: ElementsFlap 2 Title: CompoundsFlap 3 Title: Mixtures
7Elements Behind “Elements” Flap Inside “Elements” Flap Elements are organized on the periodic tableThere are over 100 known elementsElements are represented with a chemical symbol.The symbol is at least one letter; the first letter is always capitalizedExample: H (Hydrogen) & He (Helium)Element examples:Mg (Magnesium)C (Carbon)S (Sulfur) or S8Some elements are diatomic (2 atoms); they occur in nature in groups of twoH2, O2, Br2, Cl2
8Can it have two or more types of atoms? Can it have one type of atom? CompoundsBehind “Compounds” FlapWhat is the difference between a molecule and a compound?Type of SubstanceCan it have two or more types of atoms?Can it have one type of atom?Can it be an element?MoleculeYesCompoundYes (it must!)NoInside “Compounds” FlapThere are millions of compounds!Examples: H2O, H2O2, FeO, CH3All compounds are molecules, but not all molecules are compounds O2 is a molecule, but it’s not a compound
9Mixtures Behind “Mixtures” Flap Inside “Mixtures” Flap Homogeneous MixturesHeterogeneous MixturesThese mixtures are evenly distributed and may look like pure substances because they are completely mixed into a single phaseAlso called solutions – contain a solute (the substance being dissolved) dissolved in a solvent (the substance doing the dissolving)Examples: salt water, Kool-aid, brassThese mixtures are not evenly distributedThe substances are considered insoluble because one substance will not dissolve in the otherExamples: oil and water, Chex mix, chicken noodle soup
10Venn Diagram – Comparing elements, compounds, and mixtures Place the letter for each description in its location on the Venn DiagramPure substanceOnly one type of atomTwo or more types of atomsAlways homogeneousCan be homogeneousMatterCan be two or more phasesThere are about 100 different onesTwo elements joined by chemical bondsCan be separated by physical changeCan be broken down by chemical changeB, HA, DE, FK, IG, JC