ChemistryChapter 3

Properties and Classification of Matter

Chemistry-Matter and ChangeGlencoe

Last revision Fall 2007

MatterMatter – anything that has mass and volume.

Mass – the amount of material that makes an object

Volume – the amount of space an object takes

Light from a lighthouse?

The pen/pencil you are writing with?

Your textbooks? Your

thoughts?

Heat from a fire?

All matter is made of tiny little particles called atoms.

There are 90 There are 90 different different

naturally existing naturally existing atoms and 25 atoms and 25

man made ones.man made ones.

They can all They can all be found be found

on the on the periodic periodic table.table.

2 hydrogen atoms & 1

oxygen atom

1 sodium atom & 1 chlorine

atom

Everything about you and everything around you is made of these atoms or combinations or mixtures of these atoms..

Salt (NaCl)

For example:

Water (H2O)

Properties of Matter

Physical Property - a quality or condition of matter that can be observed or measured without changing the arrangement of atoms that make it

Examples:• color• size• shape• state of matter• texture

These properties can usually be observed using our senses or measured with equipment in the lab.

•Mass•Length•Volume•Boiling point•Melting point

Chemical Properties – property that can only be observed when the arrangement of particles that make the matter are altered

These properties usually tell you how a substance will react in the presence of a second substance.

Examples:Iron reacts with oxygen to form rust.

Metals react with acids to form hydrogen gas.

Changes in Matter

Physical Changes – changes in matter that do not alter the arrangement of atoms that make the matter

Changes in size, shape, and STATE OF MATTER.

Examples:crumpling up a piece of paper

breaking a stick in halfmelting ice

salt dissolving in water

Chemical Changes - changes in matter that DO alter the arrangement of atoms that make the matter

Because you can’t see the particles to determine if arrangement has changes, you can look for clues that tell you a chemical change has occurred.

Clues of a Chemical Change:

Identify the following as either a physical property or a chemical property.

Property Physical Chemical

a shirt is red

sodium is so soft it can be cut with a knife

potassium reacts vigorously with water

paper is flammable

water boils at 100 oC

Identify the following as either a physical change or a chemical change.

Change Physical Chemical

burning toast

breaking a glass

melting butter

leaves changing color

fireworks exploding

Intensive vs. Extensive

Intensive properties are properties unique to a pure substance. It is a property that can be used to identify it.

Ex: Extensive properties are properties

that many kinds of substances can have and will not identify the substance.

Now that we can describe matter, we can begin to classify it

Matter-anything with mass and volumeMatter is separated into two categories:

pure substances and mixtures.Matter

Pure Substance – a substance made of the same kind of atoms or compounds having a unique set of chemical and physical properties

The two categories of pure substances are elements and compounds

Pure Substance

Element simplest type of pure substance made of only 1 kind of atom

Examples:

all particles are identical cannot be separated by a physical

or a chemical change

Compounds made of two or more different kind of

elements chemically combined together in a specific ratio

Examples:

elements in a compound can only be broken apart by a chemical change

Classify the following as either an element or a compound.

Mixtures physical blend of two or more pure

substances. can be separated by a physical

change

The two categories of mixtures are homogeneous and heterogeneous.

Mixtures

Homogeneous Mixtures mixtures that are uniform in composition on

the atomic level. all parts of the mixture have the same

concentration of matter. Different parts of the mixture can not be

identified (transparent appearance for solutions)

Alloys: solution of metal also called a solutionExamples:Salt water, vinegarLemonade, alcohol3% H2O2 and H2O solution

Steel, solder or 14 K gold

Heterogeneous Mixtures mixtures that are not uniform in

composition all parts of the mixture are not the

same the different parts can usually be

easily identified from one anotherExamples:

rocks and sandsalt and pepper

oil and water

Classify the following as either a homogeneous mixture or a

heterogeneous mixture.

Classify the following everyday common objects as a homogeneous mixture or a heterogeneous mixture.

Jelly Pizza

Soda

Lotion Chunky Peanut Butter

Mixed Nuts

Matter

Pure Substances Mixtures

Element Compound Homogeneous Heterogeneous

State of Matter- Matter can be solid, liquid, gas or plasma depending on how much kinetic

energy (or motion) they have.

Solid: Particles vibrate in place. It has a definite volume and a definite shape.

Liquid: Particles roll around each other. It has a definite volume but no definite shape.

Gas: Particles move around colliding with one another. It has no definite volume or shape.

Plasma: Particles are so hot and excited that the electrons leave the nucleus and matter is ionized or charged

Matter in Motion

The Kinetic Molecular Theory states that atoms and molecules are always in motion.

Remember, the temperature of a substance is the measure of its kinetic energy.

That energy can only do one thing at a time:

1.Change the state of the substance.

2.Increase the temperature of a substance.

Depositing

Sublimating

Boiling

Condensing

Melting

1. Changes in the states of Matter

2. Heating Curve

This curve can also work in reverse if energy is being taken away.

Absolute Zero

is the temperature at which all motion of particles stops.

Scientists have yet to reach it.

Separating Mixtures

Mixtures are physical blends of two or more pure substances.

Since they are mixed physically, they can be separated into the individual pure substances by physical changes.

Contrast Compare Contrast

Compare and Contrast the two types of mixtures..

Methods of Separating Mixtures using:

Distillation - method of separating components of a solution using their boiling points.

• involves 3 stages and both are state of matter changes

(1) The solution is boiled to vaporize one component of the solution with the lower boiling point.

(2) As soon as the temperature starts to rise, the vapor stops being collected since this rise in temperature indicates the end of a phase change.

(3) The vapor is cooled to turn it back into a liquid

Freezing and Boiling Points

Example: Separate alcohol and water

1. Dissolve substance that is soluble in water.

2. Filtration - uses a filter of porous material to separate a mixture of liquid and insoluble components

3. Evaporate the liquid portion of a solution which changes to a gas or vapor leaving a solid behind

Solubility

Example: Separate sand and salt.

Magnetism - used to separate components of a mixture when one is attracted to a magnet and one is not

Chromatography - method of separation used to see what colors make up an ink or substance containing different molecules.

Steps of Chromatography1. Material to be separated

is spotted on chromatography paper

2. Paper is dipped into a solution that will be

absorbed by the paper and moves up

3. Some colors move more than others and separate