Chemistry: The Study of Chemistry: The Study of MatterMatter

What is Chemistry?What is Chemistry?

The study of the matter, its The study of the matter, its composition, properties, and the composition, properties, and the changes it undergoes.changes it undergoes.

A natural science.A natural science. a language with its own vocabulary.a language with its own vocabulary. a way of thinking.a way of thinking.

Review of matter:Review of matter:

Matter: anything Matter: anything that takes up space that takes up space (volume) and has a (volume) and has a mass.mass.

Physical Properties: Physical Properties: like different like different densities, melting densities, melting points, boiling points, boiling points, freezing points, freezing points, color or points, color or smellssmells

Chemical Chemical Properties: A good Properties: A good example of example of chemical chemical properties is the properties is the way elements way elements combine with each combine with each other in reactionsother in reactions

Review of states of matterReview of states of matter

Solid

Liquid

Gas

Definite Volume?

YES

YES

NO

Definite Shape?

YES

NO

NO

Temperature increase

Small Expansion

Small Expansion

Large Expansion

Compressible?

NO

NO

YES

Solid Liquid Gas

Melt Evaporate

CondenseFreeze

Kinds of Change:Kinds of Change:

physical changephysical change: : no new no new substance is formed, properties substance is formed, properties such such as size, shape, colour or state may as size, shape, colour or state may change (eg. change (eg. Boiling water) The reverse Boiling water) The reverse is possibleis possible

chemical changechemical change: : new substances new substances (with new properties) (with new properties) are formed from 2 are formed from 2 or more different elements. (eg. Rusting or more different elements. (eg. Rusting

of iron) The reverse is not possibleof iron) The reverse is not possible

PropertiesProperties Words that describe matter Words that describe matter

(adjectives)(adjectives) Physical PropertiesPhysical Properties- a property that - a property that

can be observed and measured can be observed and measured without changing the composition of without changing the composition of the substance.the substance.

Chemical PropertiesChemical Properties- a property that - a property that can only be observed by changing can only be observed by changing the composition of the substance. the composition of the substance.

Glossary:Glossary:

Pure substance: contains one type of Pure substance: contains one type of particle. Ex: Elements and particle. Ex: Elements and compounds:compounds:

Mixture: contains two or more types Mixture: contains two or more types of particles intermingling, no of particles intermingling, no chemical bonding. Types are chemical bonding. Types are homogeneous and heterogeneous.homogeneous and heterogeneous.

Composed of two or Composed of two or more different atomsmore different atoms

Can be broken down Can be broken down by chemical methods by chemical methods and each part will have and each part will have different propertiesdifferent properties

ExamplesExamples: : waterwater (H (H22O), 2 atoms O), 2 atoms of hydrogen, I atom of of hydrogen, I atom of oxygen)oxygen)saltsalt (NaCl), 1 atom of (NaCl), 1 atom of sodium, 1 atom of sodium, 1 atom of chlorinechlorine

An element is a An element is a substance made up of substance made up of only one kind of atomonly one kind of atom

The periodic table The periodic table arranges elements arranges elements according to their according to their propertiesproperties

Compound or MixtureCompound or MixtureCompound Mixture

One kind of matter-Molecule or atom

More than one kind of matter- different molecules or atoms

Made during a

chemical change Made through a

physical change

Definite and uniform composition

Variable in composition

Which is it?Which is it?

ElementCompoundMixture

HeterogeneousHeterogeneous

2 or more parts 2 or more parts can be seencan be seen

Different kinds Different kinds of particles stay of particles stay together.together.

Mechanical Mechanical mixingmixing

Ex: sand and Ex: sand and salt, blood, milksalt, blood, milk

HomogeneousHomogeneous

Appear to be one Appear to be one substancesubstance

Particles are Particles are intermingledintermingled

May be solutions May be solutions (something (something dissolved)dissolved)

Ex: air, salt waterEx: air, salt water

SolutionsSolutions Homogeneous mixture with molecules Homogeneous mixture with molecules

mixed uniformlymixed uniformly Solutions occur between any state of Solutions occur between any state of

matter.matter.Solid in liquid- Kool-aidSolid in liquid- Kool-aid

Liquid in liquid- antifreezeLiquid in liquid- antifreeze

Gas in a liquid – carbonated beveragesGas in a liquid – carbonated beverages

Gas in gas- airGas in gas- air

Solid in solid - brassSolid in solid - brass

Liquid in gas- water vaporLiquid in gas- water vapor

SolutionsSolutions

Like all mixtures, the components Like all mixtures, the components keep their own properties.keep their own properties.

Components can be separated by Components can be separated by physical meansphysical means

Chemical symbolsChemical symbols

There are 112 elementsThere are 112 elements Each has a 1 or two letter Each has a 1 or two letter symbolsymbol First letter always capitalized second First letter always capitalized second

nevernever Don’t need to memorizeDon’t need to memorize Some from Latin or other languagesSome from Latin or other languages

Chemical ReactionsChemical Reactions

When one or more substances are When one or more substances are changed into new substances.changed into new substances.

Reactants- stuff you start withReactants- stuff you start with Products- What you makeProducts- What you make NEW PROPERTIESNEW PROPERTIES Not easily reversedNot easily reversed

Indications of a chemical Indications of a chemical reactionreaction

Energy absorbed or releasedEnergy absorbed or released Color changeColor change Gas producedGas produced PrecipitatePrecipitate-- solid that separates from solid that separates from

solutionsolution Not easily reversedNot easily reversed ALWAYS THERE IS A NEW SUBSTANCE!ALWAYS THERE IS A NEW SUBSTANCE!

Conservation of Mass Conservation of Mass

Mass can not be created or Mass can not be created or destroyed in ordinary (not nuclear) destroyed in ordinary (not nuclear) changes.changes.

All the mass can be accounted for.All the mass can be accounted for.

What about nuclear?What about nuclear?

E = mcE = mc22 energy = mass x (speed of light)energy = mass x (speed of light)22 speed of light = 3 x 10speed of light = 3 x 1088 A little mass can make a lot of A little mass can make a lot of

energyenergy Law of Conservation of Mass - EnergyLaw of Conservation of Mass - Energy

the total of the mass and energy the total of the mass and energy remains the same in any changeremains the same in any change

EnergyEnergy

The ability to do The ability to do work.work. Work - Work - cause a change or move an cause a change or move an

object.object. Many types- all can be changed into Many types- all can be changed into

the other.the other.

Types of energyTypes of energy

Potential- stored energyPotential- stored energy Kinetic Energy- energy something Kinetic Energy- energy something

has because its movinghas because its moving Heat- the energy that moves Heat- the energy that moves

because of a temperature difference.because of a temperature difference. Chemical energy- energy released or Chemical energy- energy released or

absorbed in a chemical change.absorbed in a chemical change. Electrical energy - energy of moving Electrical energy - energy of moving

chargescharges

Types of EnergyTypes of Energy

Radiant Energy- energy that can Radiant Energy- energy that can travel through empty space (light, travel through empty space (light, UV, infrared, radio)UV, infrared, radio)

All types of energy can be converted All types of energy can be converted into others.into others.

If you trace the source far enough If you trace the source far enough back, you will end up at nuclear back, you will end up at nuclear energy.energy.

Conservation of EnergyConservation of Energy

Energy can be neither created or Energy can be neither created or destroyed in ordinary changes (not destroyed in ordinary changes (not nuclear), it can only change form.nuclear), it can only change form.

Its not just a good idea, its the Its not just a good idea, its the lawlaw..

Assigned reading:Assigned reading:

Page 6-8 and 10-16Page 6-8 and 10-16 Be able to define or explain the Be able to define or explain the

following terms/conceptsfollowing terms/concepts Types of knowledgeTypes of knowledge Pure/applied sciencePure/applied science Scientific methodScientific method Rules of experimentationRules of experimentation Laws, theories and modelsLaws, theories and models