Matter chapter 3

Matter Anything that has mass & occupies space Mass: measured in grams or kilograms Space/volume: measured in liters or cm3

Phases SOLIDS LIQUIDS GASES

Solid: definite volume definite shape

Liquid definite volume indefinite shape takes the shape of container

Gas indefinite volume indefinite shape takes the shape and volume of container

States of Matter How are the particles packed in each phase? How do the particles move in each phase? Why do liquids and gases flow? Why are gases so easy to compress?

4th Phase of matter Plasma exists in stars electrons are stripped from atoms

Physical Properties Describe appearance & form of matter Descriptive words: color, texture, luster, odor solid, liquid, gas Measurements: a number and a unit

Intensive properties Physical Constants independent of sample size Density, freezing point, and melting point Solubility in water (g/ml)

Extensive Properties Extensive properties (mass  volume) depend on quantity (amount) of matter in sample

Chemical Properties Describe how: matter behaves in presence of other matter matter changes into another kind of matter examples: Flammability resistance to corrosion ability to neutralize acids or bases

Properties of Copper Physical Prop. reddish brown shiny malleable Ductile good conductor density = 8.92 g/cm3 mp = 1085C bp = 2570C Chemical Prop. reacts to form green copper carbonate forms deep blue solution when in contact with NH3 forms new substances with HNO3

Physical Change form or appearance of matter may change but identity remains same cutting, crushing, grinding,tearing phase changes dissolving

Dissolving Dissolving is physical change think of sugar in water still have sugar – sugar molecules just spread out between water molecules C6H12O6(s)  C6H12O6(aq)

Phase Changes Phase changes are physical changes No new substance is created (chemical formula stays the same) Ex: ice melting: H2O(s)  H2O(l) water boiling: H2O (l)  H2O(g)

Chemical Change Ex: 2H2O(l)  2H2(g) + O2(g) chemical change - identity of matter is changed new substance with own unique properties is formed chemical formula changes Ex: 2H2O(l)  2H2(g) + O2(g)

Burning common name for oxidation reaction indicates matter reacting with oxygen is chemical change - original substance is changed into new kind(s) of matter Ex: CH4(g) + 2O2(g)  CO2(g) + 2H2O(g)

What kinds of matter are there?

Matter Substances Mixtures Mixtures  Separated by physical methods Elements Compounds Heterogeneous Homogeneous Mixtures  Separated by physical methods Compounds  Separated by chemical methods

Element substance that: formulas have 1 uppercase letter cannot be broken down (decomposed) into simpler substance only 1 kind of atom has definite properties formulas have 1 uppercase letter

Element Song

Atom smallest particle of element that retains properties of element smallest particles of element that can undergo a chemical reaction

Compounds 2 or more elements chemically combined in a definite ratio properties are different from those of elements formed from homogeneous broken into elements by chemical decomposition reaction formulas have 2 or more uppercase letters

Cl(g) Na(s) 2Na + Cl2  2NaCl NaCl(s)

Mixtures combo of 2 or more pure substances physically combined not chemically combined each substance retains its own identity and properties

Mixtures variable composition no unique properties (think of sugar and salt mixed together) separated by physical methods may be homogeneous or heterogeneous

Types of Mixtures

homogeneous: constant composition throughout, single phase ex: solutions (all 3 phases) such as air, windex, kool-aid

heterogeneous: See a boundary or regions that look different ex: ice water, granite suspensions, colloids

Suspensions particles in suspensions are larger than those in solutions components of suspension can be evenly distributed by mechanical means (shaking the contents) but components will settle out

Colloids particles larger than size of molecule but smaller than particles seen with naked eye colloidal dispersion consists of colloids in a dispersing medium ex: whipped cream, mayonnaise, milk, butter, gelatin, jelly, colored glass

Colloid subtypes

Aerosols: solid or liquid particles in gas Ex: Smoke: solid in a gas Fog: liquid in a gas

Sols: solid particles in a liquid ex: Milk of Magnesia (solid magnesium hydroxide in water)

Emulsions: liquid particles in liquid ex: mayonnaise: oil in water

Gels: liquids in solid ex: gelatin: protein in water quicksand: sand in water

Hints for Mixtures solutions in gas & liquid phases transmit light particles not big enough to scatter light look translucent suspensions look cloudy particles big enough to scatter light settle on standing

CuSO4(aq) source source

        Particle Diagrams atoms of a monatomic element         molecules of a diatomic element        

         Particle Diagrams molecules of a triatomic compound         mixture: monatomic element, diatomic element, triatomic compound             

Separating Mixtures physically combined separation based on physical properties sorting: size & appearance filtration: size solid in liquid distillation: different bp’s liquids mixed crystallization: solubility solid in liquid magnet: magnetization chromatography: solubility liquids mixed “Travel” ability

Distillation

Paper Chromatograhy

Crystallization

Conservation of Mass mass begin with = mass end up with # of atoms before = # of atoms after