cm19 - Chapter 2 Chapter Matter and Change What is Matter?...

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Unformatted text preview: Chapter 2 Chapter Matter and Change What is Matter? What Matter is anything that takes up space and has mass. and Mass is the amount of matter in an object. object. Mass is resistance to change in motion along a smooth and level surface. along Examples Types of Matter Types Substance- a particular kind of matter particular pure pure Mixture- more than one kind of matter Properties Properties Words that describe matter (adjectives) Physical Properties- a property that can property be observed and measured without changing the substance. changing Chemical Properties- a property that property can only be observed by changing the type of substance. Properties Properties Words that describe matter (adjectives) Extensive Properties- only depends on only the amount of matter the Intensive Properties- only depends on only the type of matter, not the amount the Used to identify a substance States of matter States Solid- mater that can not flow and has mater definite volume. definite Liquid- definite volume but takes the definite shape of its container (flows). shape Gas- a substance without definite substance volume or shape and can flow. volume Vapor- a substance that is currently a substance gas but normally is a liquid or solid at room temperature. room States of Matter States Definite Definite Temp. ComVolume? Shape? increase pressible? Solid Liquid Gas YES YES Small Expans. Small Expans. Large Expans. NO YES NO NO NO NO YES Freeze Melt Condense Evaporate Solid Liquid Gas States of Matter States There are more Plasma – high temperature low pressure high – electrons separate from nucleus – Most common in the universe More at very low temp – Bose- Einstein condensate – Quantum superfluids Another Way to Change States Another Pressure For some substances it will turn solids For to liquids to For others it will turn liquids to solids – Silly putty Will turn gas to liquid– Compressor in refrigerator and AC Physical Changes Physical A change that changes appearances, change without changing the composition. without Examples? Chemical changes - a change where a new form of matter is formed. new Also called chemical reaction. Examples? Not phase changes – Ice is still water. Made up of two substances. Variable composition. Heterogeneous- mixture is not the mixture same from place to place. same Chocolate chip cookie, gravel, soil. Homogeneous- same composition same throughout. throughout. Kool-aid, air. Every part keeps its properties. Mixtures Mixtures Only a physical change- no new matter Filtration- separate solids from liquids Filtrationwith a barrier with Distillation- separate because of Distillationdifferent boiling points different – Heat mixture – Catch vapor in cooled area Chromatography- different substances Chromatographyare attracted to paper or gel, so move at different speeds at Separating mixtures Separating Chromatography Chromatography A part of a sample with uniform part composition, therefore uniform properties properties Homogeneous- 1 phase Heterogeneous – more than 1 Phases Phases Solutions Solutions Homogeneous mixture Mixed molecule by molecule Can occur between any state of matter. Solid in liquid- Kool-aid Liquid in liquid- antifreeze Gas in gas- air Solid in solid - brass Liquid in gas- water vapor Solutions Solutions Like all mixtures, they keep the Like properties of the components. properties Can be separated by physical means Not easily separated- can be separated Not can without creating anything new. without Elements- simplest kind of matter Cannot be broken down into simpler All one kind of atom. Compounds are substances that can be broken down by chemical methods broken When they are broken down, the pieces When have completely different properties than the compound. Salt Salt Made of molecules- two or more atoms Made molecules two stuck together stuck Substances Substances Compound or Mixture Compound Compound One kind of pieceMolecules Making is a chemical change Only one kind Mixture More than one kind Molecule or atoms Making is a physical change Variable composition Which is it? Which Mixture Element Compound Chemical Reactions Chemical Another name for chemical change When one or more substances are When changed into new substances. changed Reactants- stuff you start with Products- What you make NEW PROPERTIES Because each substance has its own Because properties properties Indications of a chemical reaction Indications Energy absorbed or released Color change Odor change Precipitate- solid that separates from solution solution Not easily reversed Only clues not certainty Chemical symbols Chemical There are 116 elements Each has a 1 or two letter symbol Each symbol First letter always capitalized second First never never Don’t need to memorize Some from Latin or other languages Chemical symbols Chemical Used to write chemical formulas Subscripts tell us how many of each Subscripts atom atom H 2O C3H8 HBrO3 Conservation of Mass Mass can not be created or destroyed Mass in ordinary (not nuclear) changes. in All the mass can be accounted for. Mass at the start = mass at end Energy Energy The ability to do work. The work. Work - cause a change or move an Work object. object. Many types- all can be changed into the Many other. other. Types of energy Types Potential- stored energy Kinetic Energy- energy something has because its moving because Heat- the energy that moves because of a temperature difference. of Chemical energy- energy released or absorbed in a chemical change. absorbed Electrical energy - energy of moving charges charges Types of Energy Types Radiant Energy- energy that can travel through empty space (light, UV, infrared, radio) infrared, Nuclear Energy – Energy from changing the nucleus of atoms changing All types of energy can be converted All into others. into If you trace the source far enough back, If you will end up at nuclear energy. you Conservation of Energy Conservation Energy can be neither created or Energy destroyed in ordinary changes (not nuclear), it can only change form. nuclear), Its not just a good idea, its the law. Its law What about nuclear? What E = mc2 energy = mass x (speed of light)2 speed of light = 3 x 108 A little mass can make a lot of energy Law of Conservation of Mass - Energy the total of the mass and energy remains the same in any change remains ...
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