2Classification of Matter ElementsDraw this chart!, leave space to define the termsPure SubstancesCompoundsMatterHomogeneousMixturesHeterogeneous
3Pure Substances vs. Mixtures A pure substance is made of only one kind of material and has definite properties.Matter that consists of two or more substances mixed together but not chemically combined is called a mixture.
4Pure Substances: Elements are the simplest pure substance. Examples: hydrogen, carbon, and oxygen.The smallest particle of an element that has the properties of that element is called an atom.
5Pure substances:Compounds are pure substances that are made of more than one element bound together.Examples: water (H2O), and carbon dioxide.A molecule is formed when two or more atoms chemically combine.Example: water (H2O), O2
6MIXTURES Heterogeneous vs. Homogeneous Homogeneous matter (solutions): matter that has identical properties throughout.Examples: salt water, gravy, whipped creamHeterogeneous matter: matter that has parts with different properties.Examples: granite, soil, potpourri, cookies
7LIQUID MIXTURES Miscible vs. Immiscible Miscible Mixture: liquids that mix evenly, forming a homogeneous solution. Example: Soda mixed with KoolaidImmiscible Mixture: liquids that DO NOT mix evenly, forming a heterogeneous mixture. Example: Oil mixed with Water
8EXAMPLESWhat type of matter are each of the following… ?
14Air Homogeneous mixture of: Nitrogen, N2 78.08% Oxygen, O2 20.95% Argon, Ar 0.93%Carbon dioxide, CO %Neon, Ne %Helium, He %Methane, CH %Krypton, Kr %Nitrogen(I) oxide, N2O %Hydrogen, H %Xenon, Xe %Ozone, O %Homogeneous mixture of:Many gases make up mixture, but it looks like it is all one gas.
26This includes you and me! Giggitty, Giggitty, Goo! We are all made of atoms…and only atoms.This includes you and me! Giggitty, Giggitty, Goo!
27Currently we have about 117 kinds of atoms Currently we have about 117 kinds of atoms. In the natural world there exists 92 different kinds of atoms.The others have been artificially produced in laboratories.The Elements Song
28We call each kind of atom an element, and give it a specific name and symbol. Copper CuGold Au
34Of course real atoms don’t look anything like this you imbecile! Atoms are made up of protons, neutrons, and electrons.Of course real atoms don’t look anything like this you imbecile!Protons and neutrons are found in the nucleus of atoms -- roughly at the centerElectrons travel around the nucleus.
35It would be sweet if atoms really were this huge! Different kinds of atoms, or elements, are different because they have different numbers of protons.It would be sweet if atoms really were this huge!
36We list the elements by their atomic numbers - the number of protons they have. Helium, number 2Hydrogen, number 1In several cases the atomic weights are in parentheses. This indicates that these elements have no stable isotopes; that is, they are radioactive. The value enclosed in parentheses and used for the atomic weight is the atomic mass number of the most stable known isotope, as indicated by the longest half-life.
37Physical PropertiesPhysical properties: characteristics that can be observed without changing the identity of the substance.Examples:massvolumecolorshapetexturedensity
38Physical ChangesPhysical change: a change in the physical form or properties of a substance that occurs without a change in composition.Examples:meltingfreezinggrindingdissolving
39Chemical PropertiesChemical property: describes a substance’s ability to change into a different substance.Examples:flammabilityreactivity
40Chemical ChangesChemical change: occurs when a substance changes composition by forming one or more new substances. (bonds are broken and bonds are formed)Example:HCl + NaOH NaCl + H2O
41Indications of a Chemical Change… Heat in Endothermic (feels cold)Heat out Exothermic (feels hot)Gas is given off (fizzing or bubbles)Color ChangeNew Substance is Formed
47Kinetic TheoryAll matter is made of atoms and molecules that act like tiny particles.These tiny particles are always in motion. The higher the temp., the faster the particles move.At the same temp., more massive (heavier) particles move slower than less massive (lighter) particles. (inertia)
48SOLIDS Definite shape? YES Definite volume? Molecules in a solid are tightly packed and constantly vibrating.Eureka: Molecules in Solids
49LIQUIDS Definite shape? NO Definite volume? YES Some liquids flow more easily than others. The resistance of a liquid to flow is called viscosity.Honey has a high viscosity compared to water.Eureka: Molecules in Liquids
50GASES Definite shape? NO Definite volume? The particles in a gas are spread very far apart, but can be compressed by pumping them into a restricted volume.Eureka: Molecules in Gases
51Phase Changes (Changes of State) Changes in phase are examples of physical changes.Melting: solid liquidFreezing: liquid solidVaporization: liquid gasCondensation: gas liquidSublimation: solid gasDeposition: gas solid
52Changes of State SOLID GAS LIQUID Melting Vaporization Condensation DepositionSublimationVaporizationCondensationMeltingFreezingLIQUID
53Energy Transfers ENERGY is the ability to change or move matter. Energy is ABSORBED when substances melt or evaporate.NOTE: our bodies cool down when our sweat evaporates.Energy is RELEASED when substances freeze or condense.
54Melting The change of state from solid to liquid. Energy (heat) is absorbed by the substance that is melting.
55FreezingThe change of state from liquid to solid. Opposite of melting.Energy (heat) is released by the substance undergoing freezing.
56Evaporation Energy (heat) is absorbed by the liquid The change of state at the surface of a liquid as it passes to a vapor. This results from the random motion of molecules that occasionally escape from the liquid surface.Energy (heat) is absorbed by the liquidCan happen at any temperature
57CondensationThe change of state from gas to liquid. The opposite of evaporation.Energy (heat) is released by the gas to become a liquid.
58Boiling Change from state from a liquid to a gas. Occurs throughout the liquid.boiling point/temperature is determined by pressureEnergy (heat) is absorbed by the liquid for it to boil and produce gas.
59Phase Change Graph*Boiling & freezing points depend on the pressure.
60Water at normal pressure (1 atm): For water at normal (every day) pressures:Melting/freezing point:Condensing/boiling point:0 oC (32oF)100 oC (212oF)
61Phase Change Graph 0°C 100°C *Boiling & freezing points depend on the pressure.