2Composition and Properties of Matter Composition of Matterwhat matter is made ofEx: Center of the EarthProperties of Matterwhat the matter is like; how matter behaves.Ex: Earthquakes
3Matter: The Substance of the Known Universe anything that has mass and volumeExamples of matter: solids, liquids, gasesNOT examples of matter: ideas (truth, love, loyalty), heat, energyMass:the amount of matter in an objectMass is related to weight, but it is NOT the same thing.
4Mass Vs. Weight What does an object’s weight depend on? how hard gravity pulls on itthis will vary, depending on locationAn object’s mass does NOT change, no matter where it is.
5Volume Volume the amount of space an object occupies Is air matter? Air takes up space; has mass
6Simplest form of matter The most basic unit of matter is the atom. There are 109 different varieties of atom.they are listed on the Periodic TableEx: oxygen (O), carbon (C), hydrogen (H)Often, atoms combine together to form a moleculea neutral group of atoms held together by chemical bondsEx; Carbon dioxide, water, hydrogen molecule
7How Do We Classify Matter? At the smallest level, all matter is composed of atoms.All matter can be classified as either a pure substance or a mixture.Ex: Pure Substance; pure gold (24 karat)Ex: Mixture; gold alloy (14 karat)
8Pure Substancea type of matter for which all samples have the same properties; they behave exactly the same wayThere are 2 types of pure substances, elements and compounds
9Elements and Compounds samples of a substance that contain only one type of atom.An element CAN’T be broken down into simpler substances by chemical means.the Periodic Table has 109 different elements.Examples of elements: aluminum (Al), nickel (Ni), nitrogen (N)
10Elements and Compounds Cont. Allotropes:different forms of an element in the same physical stateEx: oxygen atom, oxygen gas, ozoneO O O3Compounds:a substance made up of 2 or more different elements that are chemically combinedMethane (CH4), Water (H2O)
11Compounds Cont. Properties of Compounds: Sample problem: every sample of a particular compound has the same properties as every other sampleSample problem:In every 100 g sample of pure water, there are 11.2 g of hydrogen and 88.8 g of oxygen. How many grams of hydrogen are in a 120 g sample of pure water?
12MixturesMixtures:a combo of 2 or more substances; each retains its individual propertiesIn a mixture, there are no chemical bonds between the different substances.There are two types of mixtureshomogeneous mixtureheterogeneous mixture
13Homogeneous mixtureall regions of a homogeneous mixture are identical in composition and propertiesHomogeneous mixtures are evenly-mixed, or uniformly distributed, at the particle level, and are also referred to as solutions.Ex: soda pop, salt water, sugar water, Kool-Aidalloy = a homogeneous mixture of 2 or more metalsEx: brass = copper + zinc,
14Heterogeneous mixture some regions have different composition and properties than other regionsIn heterogeneous mixtures, the particles may appear to be evenly mixed at the macroscopic level, they are NOT uniformly-distributed at the microscopic (particle) level.Ex: Examples: tossed salad, concrete, raisin-nut bread, oil-vinegar dressing, taco
15Heterogeneous mixture Other types of Heterogeneous Mixturessuspension = appears uniform while stirred; settles when agitation stopsExamples: Quick milk, muddy water, OJ with pulp, oil & vinegar dressingcolloid = contains tiny particles that never settle outExamples: gelatin, milk, smoke, fog
16Characteristics that Distinguish Pure Substances from Mixtures 1. A pure substance has only one set of properties, but a mixture retains the properties of each of its constituents.2. The composition of a pure substance is fixed, but the composition of a mixture can vary widely.
17Physical and Chemical properties and changes All matter exhibits physical and chemical propertiesPhysical properties: color, odor, density, hardness, solubility, melting point & boiling point.Chemical properties: are those exhibited when a substance reacts w/ other substances.Ex: reactions with acids and bases and other chemicals
18Physical ChangeThe altering of shape, size, or physical state but chemical composition stays the same.Solid Liquid MeltingGas Liquid CondensationSolid Gas SublimationLiquid Solid Freezing or CrystallizingGas Solid Reverse SublimationLiquid Gas Boiling or Evaporation
19Chemical Change The atoms of a substance are rearranged A new substance(s) formed has a chemical composition that is different than the original substance(s)