Chemistry

Matter: Phases and Changes

Kinetic Molecular TheoryExplains 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

SOLID LIQUID GAS

ParticleArrangement

Closeness of Particles

Attraction between Particles

Motion of Particles

Volume

Shape

Flow

Density

SOLID LIQUID GAS

ParticleArrangement

Fixed Random Random

Closeness of Particles

Close Close Far Apart

Attraction between Particles Strong Moderate Little to none

Motion of ParticlesHeld close by their

attractions of charge

Slide over each other

Move constantly and randomly, independent

Volume Definite volume Definite volume

Takes the volume of its container

Shape Definite shapeTakes the shape of

its container Takes the shape of

its container

Flow Does not Easily Easily

Density

High High (lower than the

corresponding solid)

Low

Middlepg 7

Review Questions1. 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 MatterBottom 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 changeor

Physical change

Chemical or Physical Change?

Chemical or Physical Change?

Chemical or Physical Change?

Chemical or Physical Change?

Chemical or Physical Change?

Chemical or Physical Change?

Chemical or Physical Change?

Chemical or Physical Change?

Chemical 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.