CHAPTER 3

Matter – Properties and Change

National Standards for Chapter 3– UCP.1 Systems, order, and organization– UCP.2 Evidence, models, and explanation– UCP.3 Change, constancy, and measurement– A.1 Abilities necessary to do scientific inquiry– A.2 Understandings about scientific inquiry– B.1 Structure of atoms– B.2 Structure and properties of matter– B.3 Chemical reactions– B.6 Interactions of energy and matter– G.1 Science as a human endeavor– G.2 Nature of scientific knowledge– G.3 Historical perspectives

Vocabulary/Study Guide

• Define each term using the Glossary• Either write on the handout, or use your own

paper• This is due on Test Day (tentatively, Monday,

September 23)

Section 1: Properties of Matter

• National Standards:– UCP.1 Systems, order, and organization– A.1 Abilities necessary to do scientific inquiry– B.2 Structure and properties of matter

Objectives – Section 1

• Identify the characteristics of a substance.

• Distinguish between physical and chemical properties.

• Differentiate among the physical states of matter.• REVIEW VOCABULARY:• density: a ratio that compares the mass of an object to its

volume

New Vocabulary

states of matter physical propertysolid extensive propertyliquid intensive propertygas chemical property

vapor

• Most common substances exist as solids, liquids, and gases, which have diverse physical and chemical properties.

Substances

• Matter is anything that has mass and takes up space.

• Matter is everything around us.• Matter with a uniform and unchanging

composition is a substance.

States of Matter

• The physical forms of matter, either solid, liquid, or gas, are called the states of matter.

• Solids are a form of matter that have their own definite shape and volume.• Liquids are a form of matter that have a definite volume but take the shape of the container.

States of Matter

• Gases have no definite shape or volume. They expand to fill their container.• Vapor refers to the gaseous state of a

substance that is a solid or liquid at room temperature.

Properties of Matter

Physical property:

Extensive properties:

Give examples:

Intensive properties:

Give examples:

Chemical property:

Give examples:

Physical Properties of Matter

• A physical property is a characteristic that can be observed or measured without changing the sample’s composition.

Physical Properties of Matter

• Extensive properties, such as mass, length, and volume, are dependent on the amount of substance present.

• Intensive properties, such as density, are dependent on the what the substance is not how much there is.

Chemical Properties of Matter

• The ability of a substance to combine with or change into one or more other substances is called a chemical property.– Iron forming rust– Copper turning green in the air

Observing Properties of Matter

• A substance can change form–an important concept in chemistry.

• Both physical and chemical properties can change with specific environmental conditions, such as temperature and pressure.

Homework, Section 1

• SECTION 1 REVIEW, Page 75• Questions #2, 3• Answer with complete sentences• Finish filling in charts that were handed out in

class: States of Matter and Properties of Matter

• Due tomorrow

Section 2: Changes in Matter

• National Standards:– UCP.3 Change, constancy, and measurement– A.2 Understandings about scientific inquiry– B.2 Structure and properties of matter– B.3 Chemical reactions– B.6 Interactions of energy and matter– G.1 Science as a human endeavor– G.2 Nature of scientific knowledge– G.3 Historical perspectives

Objectives – Section 2

• Define physical change and list several common physical changes.

• Define chemical change and list several indications that a chemical change has taken place.

• Apply the law of conservation of mass to chemical reactions.• Review Vocabulary:• observation: orderly, direct information gathering about a

phenomenon

New Vocabulary

• physical change• phase change• chemical change• law of conservation of mass

• Matter can undergo physical and chemical changes.

Physical/Phase Changes

Chemical Changes

Physical Changes

• A change that alters a substance without changing its composition is known as a physical change.

• A phase change is a transition of matter from one state to another.

• Boiling, freezing, melting, and condensing all describe phase changes in chemistry.

Chemical Changes

• A change that involves one or more substances turning into new substances is called a chemical change.

• Decomposing, rusting, exploding, burning, or oxidizing are all terms that describe chemical changes.

Conservation of Mass

• The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction, it is conserved.

• The mass of the reactants equals the mass of the products.

massreactants = massproducts

• Practice Problems #5-9 on page 78

Transparency 8: Conservation of Mass

Math Transparency 2: Visualizing the Conservation of Mass

Homework, Section 2

• SECTION 2 REVIEW, Page 79• Questions #10-14 – Answer with complete

sentences• Practice Problems Page 78:5-9 – Write the

problems, then the answers. We will do some of these in class. Finish them for homework.

• Due tomorrow

Section 3: Mixtures of Matter

• National Standards:– UCP.1 Systems, order, and organization– UCP.3 Change, constancy, and measurement– A.1 Abilities necessary to do scientific inquiry– B.2 Structure and properties of matter

Objectives – Section 3

• Contrast mixtures and substances.

• Classify mixtures as homogeneous or heterogeneous.

• List and describe several techniques used to separate mixtures.

• Review Vocabulary:• substance: a form of matter that has a uniform and

unchanging composition; also known as a pure substance

New Vocabulary

• mixture distillation• heterogeneous mixture crystallization• homogeneous mixture sublimation• solution chromatography• filtration

• Most everyday matter occurs as mixtures—combinations of two or more substances.

Mixtures

• A mixture is a combination of two or more pure substances in which each pure substance retains its individual chemical properties.

• A homogenous mixture is a mixture where the composition is constant throughout.

• Homogeneous mixtures are also called solutions.

• A heterogeneous mixture is a mixture where the individual substances remain distinct.

Mixtures

Heterogeneous Mixture• A mixture that does not

blend smoothly throughout and in which the individual substances remain distinct.

• Its composition is not uniform; the substances remain distinct

• For example: salad dressing, orange juice

Homogeneous Mixture• A mixture that has constant

composition throughout; it always has a single phase.

• It will contain the same relative amount of substances, no matter the volume of each part.

• For example: silver mercury amalgam, tea, metal alloys air

Mixtures

Separating Mixtures

• Filtration is a technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture.

• Distillation is a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances.

• Crystallization is a separation technique for homogenous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substance.

Separating Mixtures

• Sublimation is the process of a solid changing directly to a gas, which can be used to separate mixtures of solids when one sublimates and the other does not.

• Chromatography is a technique that separates the components of a mixture on the basis of tendency of each to travel across the surface of another material.

Demo: Separating a Mixture

Mini-Lab: Observe Dye Separation, page 82

Homework, Section 3

• SECTION 3 REVIEW, Page 83• Questions #15, 17, 18• Answer with complete sentences• Due tomorrow

Section 4: Elements and Compounds

• National Standards:– UCP.1 Systems, order, and organization– UCP.2 Evidence, models, and explanation– A.1 Abilities necessary to do scientific inquiry– B.1 Structure of atoms– B.2 Structure and properties of matter– G.1 Science as a human endeavor– G.3 Historical perspectives

Objectives – Section 4

• Distinguish between elements and compounds.

• Describe the organization of elements in the periodic table.

• Explain how all compounds obey the laws of definite and multiple proportions.

• REVIEW VOCABULARY:• proportion: the relation of one part to another or

to the whole with respect to quantity

New Vocabulary

• element law of definite proportions• periodic table percent by mass• compound law of multiple proportions

• A compound is a combination of two or more elements.

Elements

• An element is a pure substance that cannot be separated into simpler substances by physical or chemical means.

• 92 elements occur naturally on Earth.• Each element has a unique name and a one,

two, or three-letter symbol.• The periodic table organizes the elements into

a grid of horizontal rows called periods and vertical columns called groups.

Elements

• The periodic table organizes the elements into a grid of horizontal rows called periods and vertical columns called groups.

• Elements in the same group have similar chemical and physical properties.

• The table is called periodic because the pattern of similar properties repeats from period to period.

Compounds

• A compound is a made up of two or more elements combined chemically.

• Most of the matter in the universe exists as compounds.

• Table salt, NaCl, and water, H2O, are compounds.

• Unlike elements, compounds can be broken into smaller components by chemical means.

Compounds

• Separating a compounds into its elements often requires external energy, such as heat or electricity.

• This figure shows electrolysis of water to form hydrogen and oxygen gas.

Compounds

• The properties of a compound are different from its component elements.

Law of Definite Proportions

• The law of definite proportions states that a compound is always composed of the same elements in the same proportion by mass, no matter how large or small the sample.–Ex. Water is always composed of 2 Hydrogen to 1 Oxygen

Law of Definite Proportions

• The relative amounts are expressed as percent by mass, the ratio of the mass of each element to the total mass of the compound expressed as a percentage.

Law of Definite Proportions

• This table demonstrates that the percentages of elements in sucrose remain the same despite differences in sample amount.

Law of Multiple Proportions

• The law of multiple proportions states that when different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other element in whole number ratios.– Ex. Peroxide, H2O2, and water, H2O.

–Different compounds formed from the same elements.–Hydrogen mass the same in both compounds but oxygen mass is a

2:1 ratio in peroxide to water.

Law of Multiple Proportions

Homework, Section 4

• SECTION 4 REVIEW, Page 90• Questions #25-30 – Answer with complete sentences• Practice Problems Page 88:19-23 – Write the

problems, then the answers. We will do some of these in class. Finish them for homework.

• Due tomorrow• Chapter 3 Test is tentatively scheduled for

Wednesday, September 25. – Ch. 3 Vocab/Study Guide is due on Test Day.