copyright©2004 by houghton mifflin company. all rights reserved. 1 matter and energy chapter 3

Copyright©2004 by Houghton Mifflin Company. All rights reserved.

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Matter and Energy

Chapter 3


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Common Elements• Iodine• Manganese• Chromium• Gold• Calcium• Strontium• Phosphorous• Silver• Nitrogen• Platinum• Magnesium• Titanium

• Tungsten• Arsenic• Aluminum• Copper• Barium• Tin• Uranium• Potassium• Hydrogen• Cobalt• Bismuth• Zinc

• Chlorine• Lead• Nickel• Mercury• Sodium• Oxygen• Sulfur• Fluorine• Iron• Bromine• Antimony• Carbon


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Matter:Anything that has mass and takes up space.

Sec 3.1 Properties of Matter


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• solid, liquid, gas

States of Matter

State Shape Volume Compress Flow

Solid Definite Definite No No

Liquid Indefinite Definite No Yes

Gas Indefinite Indefinite Yes Yes


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Physical Properties are the characteristics of matter that can be observed without changing its composition– Characteristics that are directly observable– Examples: color, melting point, density, volume

Chemical Properties are the characteristics that determine how the composition of matter changes as a result of contact with other matter or the influence of energy– Examples: burning, color change, decomposing


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Intensive Properties:Independent of the amount of the substance that is present.

Density, boiling point, color, etc.

Extensive Properties:Dependent upon the amount of the substance present.

Mass, volume, energy, etc.


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Classify Each of the following as Physical or Chemical Properties

The boiling point of ethyl alcohol is 78°C.

Diamond is very hard.

Sugar ferments to form ethyl alcohol.


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Classify Each of the following as Physical or Chemical Properties

The boiling point of ethyl alcohol is 78°C.– Physical property – describes inherent characteristic

of alcohol – boiling point

Diamond is very hard.– Physical property – describes inherent characteristic

of diamond – hardness

Sugar ferments to form ethyl alcohol.– Chemical property – describes behavior of sugar –

forming a new substance (ethyl alcohol)


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Changes in Matter

• Physical Changes are changes to matter that do not result in a change the fundamental components that make that substance– Example: state changes – boiling, melting, condensing– Grinding, crushing, bending, filtering

• Chemical Changes involve a change in the fundamental components of the substance– Produce a new substance– Chemical reaction– Reactants Products


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4 Indicators of a Chemical Reaction

•Produces a gas (bubbles)

•Precipitate forms (solid)

•Color change (not due to blending)

•Changes in temperature (hot or cold)


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Classify Each of the following as Physical or Chemical Changes

Iron metal is melted.

Iron combines with oxygen to form rust.

Sugar ferments to form ethyl alcohol.


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Classify Each of the following as Physical or Chemical Changes

Iron is melted.– Physical change – describes a state change, but the

material is still iron

Iron combines with oxygen to form rust..– Chemical change – describes how iron and oxygen

react to make a new substance, rust

Sugar ferments to form ethyl alcohol.– Chemical change – describes how sugar forms a new

substance (ethyl alcohol)


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Sec 3.3 Elements and Compounds

• Substances which can not be broken down into simpler substances by chemical reactions are called elements

• Most substances are chemical combinations of elements. These are called compounds.– Compounds are made of elements– Compounds can be broken down into elements– Properties of the compound not related to the

properties of the elements that compose it– Same chemical composition at all times


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Sec 3.4 Pure Substances vs. Mixtures• Pure Substances

– All samples have the same physical and chemical properties– Constant Composition all samples have the same

composition– Homogeneous– Separate into components based on chemical properties

• Mixtures– Different samples may show different properties– Variable composition– Homogeneous or Heterogeneous– Separate into components based on physical properties

• All mixtures are made of pure substances


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Classification of Matter• Homogeneous =

uniform throughout, appears to be one thing– pure substances– solutions

(homogeneous mixtures)

• Heterogeneous = non-uniform, contains regions with different properties than other regions


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Identity Each of the following as a Pure Substance, Homogeneous Mixture or

Heterogeneous MixtureGasoline

Rocky Road ice cream

Copper metal


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Identity Each of the following as a Pure Substance, Homogeneous Mixture or

Heterogeneous MixtureGasoline

– a homogenous mixture

Rock Road ice cream– a heterogeneous mixture

Copper metal– A pure substance (all elements are pure substances)


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Sec 3.5 Separation of Mixtures

• Separate mixtures based on different physical properties of the components– Physical change

EvaporationVolatility

ChromatographySolubility

FiltrationState of Matter (solid/liquid/gas)

DistillationBoiling Point

TechniqueDifferent Physical Property


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Separates homogeneous mixture on the basis of differences in boiling point.


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Filtration:

Separates solid substances from liquids and solutions.


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Chromatography:

Separates substances on the basis of differences in solubility in a solvent.


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Sec 3.6 Energy and Energy Changes

• Capacity to do work– chemical, mechanical, thermal,

electrical, radiant, sound, nuclear

• Energy may affect matter– e.g. raise its temperature, eventually

causing a state change– All physical changes and chemical

changes involve energy changes


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Heat• Heat: a flow of energy due to a temperature

difference

1. Exothermic = A process that results in the evolution of heat.• Example: when a match is struck, it is an

exothermic process because energy is produced as heat.

2. Endothermic = A process that absorbs energy.• Example: melting ice to form liquid water is an

endothermic process.


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Units of Energy

• One calorie is the amount of energy needed to raise the temperature of one gram of water by 1°C– kcal = energy needed to raise the temperature of 1000 g

of water 1°C

• joule – 4.184 J = 1 cal

• In nutrition, calories are capitalized– 1 Cal = 1 kcal


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Example - Converting Calories to Joules

251Jcal 1

J 4.184 60.1cal

joules 4.184 cal 1

Convert 60.1 cal to joules


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Energy and the Temperature of Matter• The amount the temperature of an

object increases depends on the amount of heat added (q).– If you double the added heat energy the

temperature will increase twice as much.

• The amount the temperature of an object increases depends on its mass– If you double the mass it will take twice as

much heat energy to raise the temperature the same amount.


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Specific Heat Capacity

• Specific Heat (s) is the amount of energy required to raise the temperature of one gram of a substance by one Celsius degree

C g

J 4.184 is water ofheat specific the,definitionBy

Amount of Heat = Specific Heat x Mass x Temperature ChangeQ = s x m x T


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Example – Calculate the amount of heat energy (in joules) needed to raise

the temperature of 7.40 g of water from 29.0°C to 46.0°C

Mass = 7.40 g

Temperature Change = 46.0°C – 29.0°C = 17.0°C

J 526 C17.07.40gC g

J 4.184 Heat

Specific Heat of Water = 4.184 C-g

JC g

J

Q = s x m x T


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Example – A 1.6 g sample of metal that appears to be gold requires 5.8 J to raise

the temperature from 23°C to 41°C. Is the metal pure gold?

C g

J0.20

C18 x g 1.6

J 5.8 s

C18 C23 - C41 TT m

Q s

Tms Q

Table 3.2 lists the specific heat of gold as 0.13Therefore the metal cannot be pure gold.

C gJ

copyright©2004 by houghton mifflin company. all rights reserved. 1 matter and energy chapter 3

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houghton mifflin company

boiling point of ethyl

composition of matter

state changes boiling

chemical property

physical property

chemical changes iron

chemical changes iron