Chemistry Matter: Phases and Changes

Kinetic Molecular Theory Explains the forces between molecules and the energy that they possess Matter is composed of small particles (molecules, ions, atoms). The energy and organization of these particles determines the physical state and properties of matter. All particles are in constant, random motion and possess kinetic energy. The amount of kinetic energy is directly related to temperature. Kinetic energy is transferred from one particle to another through collisions.

There are three different, common physical states of matter.

Top of pg 7 States of Matter

Solids Strong intermolecular attractions hold individual particles close together Particles vibrate Defined volumes and shapes and do not flow High densities

Liquids Particles are randomly packed and close to each other Intermolecular attractions between particles is not as strong as in solids Particles slide over each other but do not completely separate Definite volume but an indefinite shape (take the shape of their containers) Flow.

Gases Intermolecular attractions between particles is very small Particles move far apart from each other Particles are in constant, random motion, independent of each other No specific shape or volume ( take the shape of their containers ) Low densities Flow

SOLIDLIQUIDGAS Particle Arrangement Closeness of Particles Attraction between Particles Motion of Particles Volume Shape Flow Density

SOLIDLIQUIDGAS Particle Arrangement FixedRandom Closeness of Particles Close Far Apart Attraction between ParticlesStrongModerateLittle to none Motion of Particles Held close by their attractions of charge Slide over each other Move constantly and randomly, independent Volume Definite volume Takes the volume of its container Shape Definite shape Takes the shape of its container Flow Does notEasily Density High High (lower than the corresponding solid) Low

Middle pg 7

Review Questions 1.A student ran tests on a mystery substance and found that is has a definite volume, high density, and flows easily. Which state of matter is it and why? a) It is a solid because it has a definite volume and high density. b) It is a liquid because it has a definite volume and high density. c) It is a gas because it has a definite volume and flows easily. d) It is a liquid because it has a definite volume and flows easily. 2.Which of the following correctly describes the motion of particles in a solid? a)They do not move at all. b)They move rapidly around in random patterns. c) They vibrate in a set pattern. d) They flow easily, but slowly around each other.

Changes in Matter Bottom of pg 7 Physical Changes – Changes in form Crushing Tearing Changes in State – Melting – Freezing – Etc Chemical Changes – Changes in Substance – Cannot be Unchanged Burning Rust Cooking Digesting Tarnishing

Chemical change or Physical change

Chemical or Physical Change?

Which are three examples physical changes? D. gasoline burning, an egg rotting, fireworks exploding. A.water freezing, gasoline, evaporating, a nail rusting. B. water boiling, a balloon bursting, a candle melting. C. wood burning, a marshmallow melting, a paper tearing.

Which are three examples physical changes? D. gasoline burning, an egg rotting, fireworks exploding Incorrect. Chemical change. A.water freezing, gasoline, evaporating, a nail rusting Incorrect. Chemical change. B. water boiling, a balloon bursting, a candle melting Correct. Physical change. C. wood burning, a marshmallow melting, a paper tearing Incorrect. Chemical change.