The slides will provide you with:

The following slides are designed to help you in your study of matter. Matter is the basis for the second half of this course.

1) Basic definitions

2) Relationships between those definitions and the concepts they help explain.

3) Pictures and diagrams to help visualize and understand new concepts.

4) Sample problems to help prepare you for mastery assignments and quizzes.

There are fill-in-the-blank notes associated with these powerpoints. You may complete those notes for one of your graded mastery assignments.

MATTER AND MATTER AND ENERGYENERGY

Dark matter, matter we cannot see. Perhaps it doesn’t have or emit light. Dark matter, matter we cannot see. Perhaps it doesn’t have or emit light. Scientists look at galaxy clusters and determine the amount of gravity holding the Scientists look at galaxy clusters and determine the amount of gravity holding the cluster together. From this information they can determine mass. They find there cluster together. From this information they can determine mass. They find there is a great deal more mass than they can account for from the visible material, is a great deal more mass than they can account for from the visible material, thus the proposed existence of a “new” kind of matter, dark matter.thus the proposed existence of a “new” kind of matter, dark matter.

UNIT 5: CLASSIFICATION AND STRUCTURE OF MATTER

Basic matter definitions (4-9)General classification of matter (10-27)Practice problems #1 (16)Practice problems #2 (25)Practice problems #3 (27)Practice problems #4 (28)

MATTER

PART I

CLASSIFYING MATTER

Matter is anything having mass and volume.Matter is anything having mass and volume.

The Study of The Study of mattermatter and and how it changeshow it changes

Mass- the amount of matter in an objectMass- the amount of matter in an object

Mass is measured with a balance, unit is gramsMass is measured with a balance, unit is grams

• mass is related to weight but isn’t the same thing.mass is related to weight but isn’t the same thing.

• weight is dependent upon gravity.weight is dependent upon gravity.

• mass never changesmass never changes

Volume- anything that takes up space, unit L, cmVolume- anything that takes up space, unit L, cm33, , mLmL

is

6

IS AIR MATTER?

Does air have mass?Does air have volume?YES, to both, so air is matter

CompositionComposition- what matter is made of. Water is - what matter is made of. Water is made of hydrogen and oxygen (Hmade of hydrogen and oxygen (H22O), tea has O), tea has

caffeinecaffeine

PropertiesProperties-what matter is like. For example, -what matter is like. For example, water can dissolve many substances and water can dissolve many substances and caffeine is a stimulant.caffeine is a stimulant.

What caffeine is made of… What caffeine is like…

THE BASIC UNIT OF MATTER IS AN THE BASIC UNIT OF MATTER IS AN ATOMATOM

There are over 118 varieties of atoms

PERIODIC TABLE

http://www.webelements.com/scandium/

ELEMENTS contain only one type of atom.

Ex: hydrogen (H) is an element that contains only hydrogen atoms, carbon (C) contains only carbon atoms, oxygen (O) contains only oxygen atoms, etc.

Atoms of elements can combine together to form compounds.

COMPOUNDS are neutral groups of atoms held together by chemical bonds.

Ex: CO2, H2O, H2, O2

HOW DO WE CLASSIFY MATTER?

All matter is classified as either a pure substance or a mixture

Pure gold/Pure substance

24 karat

End of introductory material. Return to index

Alloy rims/ mixture of two metals

18 karat

CLASSIFYING MATTERPure substance-a type of matter where all

samples, no matter how big or small, have the same properties…they behave in exactly the same way.1. Elements2. Compounds

Elements contain one type of atom, thus they CANNOTCANNOT be broken down into simpler substances by chemical means.

Elements consist of either:single atoms, such as Carbon (C), or Sodium (Na)

groups of atoms of the same type (molecules), such

as H2, O2, Br2, etc.

ELEMENTSMONATOMIC ELEMENTS DIATOMIC ELEMENTS ALLOTROPES

Atomic nitrogen N Molecular nitrogen N2 Ozone O3

Atomic hydrogen H Molecular hydrogen H2 Graphite, buckyball

Atomic oxygen O Molecular oxygen O2

Carbon C

ALLOTROPE-different forms of an element in ALLOTROPE-different forms of an element in same physical statesame physical state

COMPOUNDS Compounds are substances made up of 2 or more different elements that are chemically combined. CO2, H2O, HCl, Na2SO4

COMPOUNDS CAN BE BROKEN DOWN INTO SIMPLER SUBSTANCES BY CHEMICAL MEANS ONLY.

COMPOUNDS HAVE DIFFERENT PROPERTIES THAN THE ELEMENTS THAT MAKE THEM UP.

Click on the links below to watch videos of compounds broken down into the substances that make them up.

Example-dehydration of sugar: C12H11O22 12C(s) + 11 H2O(g)-Sugar breaks down into carbon and water

Example-hydrolysis of water: 2H2O 2H2 + O2

• water breaks down into the hydrogen and oxygen gas which make it up.

http://www.all-science-fair-projects.com/science_fair_projects/38/819/5db524216341764c1438c1f760fddff8.html

http://earth2tech.com/2008/07/31/mit-solar-energy-storage-breakthrough/

ELEMENTS TO COMPOUND

Sodium, Na, is a soft, shiny metal that can be cut with a butter knife. When in contact with moisture it will “explode”.

Chlorine gas, Cl2, which is a green, poisonous gas once used as a chemical weapon in military operations.

COMBINED WITH…

Will Form…

Sodium metal and chlorine gas, under the right conditions, undergo a chemical change and combine to become…..

2 Na(s) + Cl2(g) 2 NaClThe final compound has properties different from the elements that formed it.

TABLE SALT!

1) We are studying CHEMISTRY, the study of ________and how it ________.

2) Matter is anything that has___ and takes up ___.

3) ___ are the basic building blocks of matter.

4) Matter can be classified as either a ___ or a ___.

5) Substances are either ___ or ___.

1. matter, changes 2. mass, space 3. atoms 4. pure substance, mixture 5. elements, compounds

Return to index

Answers:

MATTER

PURE SUBSTANCE

ELEMENT COMPOUND

Carbon (C) H2O

MIXTURE

?

NOW LETS DISCOVER MATTER AS MIXTURES

THUS FAR WE HAVE REVIEWED MATTER AS PURE SUBSTANCES.

MATTER AS MIXTURESMATTER AS MIXTURES Mixtures are combinations of 2 or more substances

where each substance retains its individual properties.

HOW ARE MIXTURES DIFFERENT FROM COMPOUNDS?

HOW ARE MIXTURES LIKE COMPOUNDS? THEY ARE MADE FROM TWO OR MORE SUBSTANCES

MIXTURES DO NOT FORM CHEMICAL BONDS.

There are two types of mixtures:

Classifying mixtures

2) HETEROGENEOUS1) HOMOGENEOUS

…a mixture that is the same throughout. A homogeneous mixture has a

composition and properties that are identical regardless of the sample

one phase

uniformly mixed

won’t settle out

small particles

Ways to identify a homogeneous mixture:

A SOLUTION is another name for a homogeneous mixture

is

… a mixture that is visibly differentthroughout. Heterogenous mixtures have a composition and properties that differ

in any given sample.

not uniformly mixed

more than one phase

will settle out

larger particles

is

Ways to identify a homogeneous mixture:

HETEROGENEOUS MIXTURESThere are special types of heterogeneous mixtures:• Suspensions-appear uniform when mixed but settle out.

– Chocolate Quik

– Muddy water

– Pulpy oj

– Oil & Vinegar dressing

• Colloids-appear uniform but they do not settle out. However, their particles are too large to be classified as a homogeneous solution.– Gelatin

– Milk

– Smoke

– Fog

– mayonnaise

TYNDALL EFFECTColloids are evenly mixed, but their particles are too

large to be considered homogeneous mixtures, which are also the same throughout.

Colloids show the Tyndall Effect. The Tyndall effect is the scattering of light as a beam passes through a colloid.

In each picture, the colloid on the left scatters the beam making it visible

MixturesSummary

Heterogeneous Mixture Homogeneous Mixture

Not evenly mixed Evenly mixed

Individual components retain their own properties

Properties of combined components are usually different than those of each component

Individual components can be easily seen

Individual components can not be easily seen

Can be easily separated Not as easily separated

Ex.: salt & pepper mix, rocks, cereal, bag of assorted candy

Ex. salt-water solution, tea, Cool-Aid drink

1. Tossed salad2. Salt water3. Kool-aid4. Muddy water5. OJ with pulp

Practice ProblemsPractice Problems

1. He 2. Ho 3. Ho 4. He 5. He 6. Ho 7. He 8. He 9. He 10. Ho

6. Tea7. Banana nut

bread8. Pizza9. Blood10. Brass

Determine whether each is a heterogeneous or homogeneous mixture:

Answers:

Return to index

• Pure Substances– Made of either elements or

compounds that are chemically bonded.

– Cannot be separated by physical means.

– When combined they take on new properties different from the original elements.

– Examples:• Glucose: C6H12O6

• Table Salt: NaCl• Oxygen Gas: O2

• Carbon Dioxide CO2

• Mixtures:– Two or more substances mixed

together but not chemically combined.

• Tea = Crushed Leaf + H2O• Rocks = minerals + sediments +

organic matter• Sugar Water = Sugar + H2O

– Each component retains its own identity; it does not change into something else.

– Can be separated by physical means

– Examples:• Sweet tea• Trail mix• Air (O2, N2, CO2, Ar)

Now, lets put it all together and determine how to tell substances (compounds and elements)

from mixtures.

Elements, Compounds, and Mixtures

Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 68

hydrogenatoms

oxygen atomshydrogenatoms

Two of the descriptions to the right apply to each bottle below. Determine the appropriate descriptions..

a. Two types of atoms evenly mixed

b. Two types of atoms chemically combined

c. One type of atom

d. Two types of atoms mixed

e. An element

f. A solution

g. A compound

h. A mixture2_______1_______ 3_______ 4_______d & h b & g c & e a & f

Return to Index

Classifying Matter

Matter

Pure Substances Mixtures

Elements Compounds

Homogeneous Heterogeneous

He, O H2O, NaCl

Tea, kool-aid Rocky Road ice cream, muddy water

Review: How matter is classified

Classify the following substances as:Pure substance, heterogeneous mixture, or homogeneous mixture

Gatorade Homogenous mixture

Fruit Loops Heterogeneous mixture

Pure substanceGasoline

Dirt Heterogeneous mixture

Sugar Crystals Pure Substance

Air Homogeneous mixture

Granite Heterogeneous mixture

Return to index

More review