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Phases of Matter. Four States Solid, Liquid, Gas, Plasma. Matter (next unit). Phases of Matter Solids Has definite shape and definite volume Does not take the shape of the container and does not take the volume of the container
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Phases of Matter Four States Solid, Liquid, Gas, Plasma
Matter (next unit) Phases of Matter Solids Has definite shape and definite volume Does not take the shape of the container and does not take the volume of the container Atoms or molecules are well ordered into a crystalline lattice for most materials Exceptions are things like glass which is really a very slow flowing liquid
Matter Liquids No definite shape and has a definite volume Takes the shape of container and does not take the volume of the container Pretty incompressible Atoms or molecules loosely bonded to neighbors, but in close proximity Allows fluid to flow
Matter Gasses No definite shape and no definite volume Take the shape of the container and takes the volume of the container Compressible Atoms or molecules are widely separated and have little interaction with each other aside from elastic collisions
Matter • Solids are incompressible • Gases are compressible • Liquids are very slightly compressible – usually considered incompressible
Matter Which of the following does not describe the solid state? a. Rigid, fixed, constant shape b. Constant volume c. Easily compressed d. Particles vibrate in fixed position e. All describe the solid state
Matter Which of the following does not describe the liquid state? a. Particles vibrate in fixed position b. Same shape as the bottom of the container c. Constant volume d. Pourable e. All describe the liquid state
Matter Which of the following does not describe the gaseous state? a. Same shape as a closed container b. Same volume as a closed container c. Random, independent particle movement d. Easily compressed e. All describe the gaseous state
Matter Plasma Temperature is so high that outer electrons are separated from their underlying atoms No molecules exist What is a molecule Molecule - neutral group of atoms united by covalent bonds Covalent bond - chemical bond resulting from the sharing of electrons between two bonding atoms Particles are electrically charged Sun, stars, inside a fluorescent bulb
Matter • Mass • Matter - anything that has mass and occupies space • Mass - measure of the quantity of matter • Weight is different. • Weight is the force of gravity on the quantity of matter • Weight changes with location moon vs. earth • Varieties of matter • Characteristics • Pure sample = pure sample of the same • Substance - matter which has the same characteristics or properties
Matter • Element • Can not be broken down into other substances by ordinary chemical means • Periodic table of elements • 91 elements found in nature • The rest synthesized in a lab • Compounds • Substance made of two or more elements chemically combined • Compounds can be decomposed into simpler substances • Combined in definite proportion by mass • The chemical and physical properties are different from those of its constituents
Matter • Compounds can be formed from simpler substances by chemical change, and they can be decomposed into simpler substances by chemical change • Math problems • In every 100 g sample sample of water 11.2 g is hydrogen and 88.8 g is oxygen. How many grams of hydrogen is in a 140.0 g sample of water? • Sucrose (table sugar) is 42.1% carbon ( C ), 6.4% hydrogen (H), and 51.5% oxygen. How many grams of C do you consume when you eat 50 g of sugar?
Matter • Mixtures • Consists of two or more substances, each which retains its individual properties • Does it separate into 2 or more layers? • Does it have to separate into 2 or more layers? • Examples • Element with element • A compound is mixed with one or more compound(s) • One or more element(s) with one or more compound(s) • Characteristics • Mixture retains properties of constituents • Homogeneous mixture - prefix homo = same • Heterogeneous mixture - prefix hetero = different
Matter • Physical and Chemical Properties • Physical - Characteristics that can be observed w/o production of a new substance • Color • Odor • Taste • Hardness • Density • Melting point (MP) and Boiling point (BP) • Metals – special characteristics • Malleable- hammered into sheets • Ductile – drawn into wires • Luster – shine of metal
Matter • Chemical- interaction with other substances to produce new substances • Iron – rust • Nitrogen – does not interact w/ most things as a gas • Physical and Chemical Change • Physical change – one or more physical properties of a substance are changed w/o change in the substances chemical properties or composition
Matter • Chemical change – change that results in the production of one or more substances that differ in chemical properties and composition from the original substance • Change in energy – every change in matter involves an energy change • Physical energy change is not as noticeable crystallization, freezing = high energy release melting, evaporation = low energy • Chemical energy change more noticible explosions, burning = high energy formation of hydrogen gas, oxygen gas=low energy
MatterEnergy and Phase Change Adding heat at a constant rate T Time
Matter Energy and Phase Change Adding heat at a constant rate T Boiling Melting Time
Matter • Conservation of mass • Law of conservation of mass • Matter can not be created or destroyed • For ordinary chem change this holds true • Lavoisier – closed container = no change, open container = change • Relative abundance • Free state/Elemental state – elements alone or uncombined • Combined state – elements combined w/ other elements (most elements occur in nature only in combined state) • Symbols of the elements – chemistry reference table pg. 11-12
Matter States of matter For a given substance, all four states are possible Increase temperature and a PHASE CHANGE occurs Solid > Liquid > Gas > Plasma
Matter Phase changes Evaporation Condensation Boiling Melting Freezing
Water Molecule Two Hydrogen Atoms, One Oxygen Atom - - + +
Matter Evaporation Liquid cools because it loses higher energy molecules or atoms Air cools because the molecules leaving give up a lot of energy to break free, so they have much lower energy after they gain their freedom Solid > Gas directly is sublimation
Condensation Condensation The opposite of evaporation Evaporation and Condensation are a SURFACE phenomenon Interaction of molecules at the liquid-air interface
Boiling Molecules break free of the liquid bonds and form little bubbles If the vapor pressure in the bubble is large enough to resist the pressure of the liquid, and the air pressure above the interface they rise and escape to the outside Remember, liquid is cooling and air is cooling
Melting and Freezing Change between liquid and solid Bonds between molecules break when solid melts Takes energy to break the bonds Freezing is the opposite of melting Molecules move slowly enough that bonds can form
Melting and Freezing Why does salt melt ice?
Energy and Phase Change For Pure Water 334 joules/gram 2256 joules/gram
Boiling Potatoes So, when you want garlic mashed potatoes and you take potatoes and cut them up and put them in boiling water, do they cook faster when the water is really bubbling compared to when the water is just barely bubbling???
