Matter

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Matter

• Chemistry
• Mrs. Kam

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Resources
Chapter Presentation
Bell Work
Test Prep
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Chapter 1
The Science of Chemistry
Table of Contents
Section 1 Describing
Matter Section 2 How Is Matter
Classified? Section 3 Physical and Chemical
Changes
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Objectives

• Distinguish between different characteristics of
  matter, including mass, volume, and weight.
• Identify and describe physical properties,
  including density.
• Identify chemical properties

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Objectives

• Distinguish between elements and compounds.
• Distinguish between pure substances and
  mixtures.
• Classify mixtures as homogenous or heterogeneous.
• Explain the difference between mixtures and
  compounds.

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Bell Work

• Look at the list of words below
• peanut butter, water, fish, light, garbage,
  time, motion, the human brain, carbon dioxide,
  air, yourself, an idea, tree, energy
• Sort the words into three categories matter, not
  matter, or not sure.
• Why is a clear definition of matter important to
  the study of chemistry?

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Matter
Physical States of Matter Properties of the
Physical States

• Solids have a fixed volume and shape that result
  from the way their particles are arranged.
• Liquids have a fixed volume but not a fixed
  shape.
• Gases have neither fixed volume nor shape.

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Matter Has Mass and Volume

• Matter is anything that has mass and volume.
• Volume is the space an object occupies.
• Mass is the quantity of matter in an object.
• Devices used for measuring mass in a laboratory
  are called balances.
• Weight is the force produced by gravity acting on
  a mass.

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Water in Three States
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Section 2 How is Matter Classified?
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Bell Work

• Make a list of the ways you have seen things
  organized.
• Which of these methods was the easiest to use and
  provided the greatest success?

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Classifying Matter

• An atom is the smallest unit of an element that
  maintains the properties of that element.
• Matter exists in many different forms but there
  are only 110 types of atoms.
• Atoms are joined together to make up all the
  different kinds of matter.

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Pure Substances

• A pure substance is a sample of matter, either a
  single element or a single compound, that has
  definite chemical and physical properties.
• Elements are pure substances that only contain
  one kind of matter. They cannot be separated or
  broken down into simpler substances by chemical
  means.
• Each element has its own unique set of physical
  and chemical properties.

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• Pure Substances

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Elements are Pure Substances

• Each elements is represented by a distinct
  chemical symbol.

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Mixtures

• A mixture is a combination of two or more
  substances that are not chemically combined.
• Air is a mixture of mostly nitrogen and oxygen.
• All the different gases in air are physically
  mixed.
• The proportions of the gases can vary.
• Water is not a mixture.
• The H and O atoms are chemically bonded
• The ratio of H to O atoms is always 2 to 1.

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Mixtures, continued Mixtures Can Vary in
Composition and Properties

• The proportion of the materials in a mixture can
  change.
• The properties of the mixture may vary.
• An alloy is a solid mixture.
• example An alloy of gold and other metal atoms
  is stronger than pure gold.
• 18-karat gold contains 18 grams of gold per24
  grams of alloy.
• 14-karat gold contains 14 grams of gold per24
  grams of alloy.

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• Particle Models for Gold and Gold Alloy

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Mixtures, continued Homogenous Mixtures

• A homogenous mixture describes something that has
  uniform structure or composition throughout.
• examples gasoline, syrup, and air
• Because any two samples of a homogenous mixture
  will have the same proportions of ingredients,
  homogenous mixtures have the same properties
  throughout.

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Mixtures, continued Heterogeneous Mixtures

• A heterogeneous mixture describes something that
  is composed of dissimilar components.
• example A mixture of sand and water is a
  heterogenous mixture.
• Any two samples of a heterogeneous mixture will
  have the different proportions of ingredients.
• Heterogeneous mixtures have different properties
  throughout.

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Examples of Mixtures

• Mixtures are either homogenous or heterogeneous.

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• Types of Mixtures

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Mixtures, continued Distinguishing Mixtures from
Compounds

• The properties of a mixture reflect the
  properties of the substances it contains.
• The properties of a compound often are very
  different from the properties of the elements
  that make it up.
• A mixtures components can be present in varying
  proportions.
• A compound has a definite composition in terms of
  the masses of its elements.

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• Classifying Matter

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Section 3

• Physical and Chemical Changes

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Changes of Matter

• Physical changes are changes in which the
  identity of a substance doesnt change.
• Changes of state are physical changes.
• Chemical changes occur when the identities of
  substances change and new substances form.

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Properties of Matter Physical Properties

• A physical property of a substance is a
  characteristic that does not involve a chemical
  change.
• Physical properties of a substance can be
  determined without changing the nature of a
  substance.
• Physical properties include texture, state,
  melting point, and boiling point.

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Properties of Matter, continued Density is the
Ratio of Mass to Volume

• The density of an object is the mass of the
  object divided by volume of the object.
• Densities are expressed in derived units such as
  g/cm3 or g/mL.
• Density is calculated as follows

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Properties of Matter, continued Density of an
Object

• The density of a substance is the same no mater
  what the size of the sample is.

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Properties of Matter, continued Density Can Be
Used to Identify Substances

• Because the density of a substance is the same
  for all samples, you can use this property to
  help identify substances.

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Properties of Matter, continued Chemical
Properties

• A chemical property a property of matter that
  describes a substances ability to participate in
  chemical reactions.
• A chemical property of many substances is that
  they react with oxygen.
• example rusting
• Some substances break down into new substances
  when heated.

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• Evidence of a Chemical Change

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Changes of Matter Evidence of a Chemical Change

• Evidence that a chemical change may be happening
  generally falls into one of the following
  categories.
• the evolution of a gas
• the formation of a precipitate
• the release or absorption of energy
• a change in temperature or the giving off of
  light energy
• a color change in the reaction system

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Test Prep
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Test Preparation
Understanding Concepts

• 1. Which of the following is best classified as a
  homogeneous mixture?
• A. blood
• B. copper wire
• C. pizza
• D. hot tea

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Test Preparation
Understanding Concepts

• 1. Which of the following is best classified as a
  homogeneous mixture?
• A. blood
• B. copper wire
• C. pizza
• D. hot tea

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Test Preparation
Understanding Concepts

• 2. Which of the following statements about
  compounds is true?
• F. A compound contains only one element.
• G. A compound can be classified as either
  heterogeneous or homogeneous.
• H. A compound has a defined ratio by mass of the
  elements that it contains.
• I. A compound varies in chemical composition
  depending on the sample size.

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Test Preparation
Understanding Concepts

• 2. Which of the following statements about
  compounds is true?
• F. A compound contains only one element.
• G. A compound can be classified as either
  heterogeneous or homogeneous.
• H. A compound has a defined ratio by mass of
  the elements that it contains.
• I. A compound varies in chemical composition
  depending on the sample size.

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Test Preparation
Understanding Concepts

• 3. Which of the following is an element?
• A. BaCl2
• B. CO
• C. He
• D. NaOH

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Test Preparation
Understanding Concepts

• 3. Which of the following is an element?
• A. BaCl2
• B. CO
• C. He
• D. NaOH

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Test Preparation
Understanding Concepts

• 4. Is photosynthesis, in which light energy is
  captured by plants to make sugar from carbon
  dioxide and water, a physical change or a
  chemical change? Explain your answer.

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Test Preparation
Understanding Concepts

• 4. Is photosynthesis, in which light energy is
  captured by plants to make sugar from carbon
  dioxide and water, a physical change or a
  chemical change? Explain your answer.
• Answer Photosynthesis is a chemical change
  because the products of the change are different
  substances than the starting materials.

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Test Preparation
Understanding Concepts

• 6. Describe the physical and chemical changes
  that occur when a pot of water is boiled over a
  campfire.

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Test Preparation
Understanding Concepts

• 6. Describe the physical and chemical changes
  that occur when a pot of water is boiled over a
  campfire.
• Answer A physical change is the conversion of
  liquid water to vapor. A chemical change is the
  reaction between wood and oxygen that generates
  heat while forming carbon dioxide and ash.

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Test Preparation
Reading Skills

• Read the passage below. Then answer the
  questions.
• Willow bark has been a remedy for pain and
  fever for hundreds of years. In the late
  eighteenth century, scientists isolated the
  compound in willow bark that is responsible for
  its effects. They then converted it to a similar
  compound, salicylic acid, which is even more
  effective. In the late nineteenth century, a
  German chemist, Felix Hoffmann, did research to
  find a pain reliever that would help his fathers
  arthritis, but not cause the nausea that is a
  side effect of salicylic acid. Because the
  technologies used to synthesize chemicals had
  improved, he had a number of more effective ways
  the work with chemical compounds than the earlier
  chemists. The compound that he made,
  acetylsalicylic acid, is known as aspirin. It is
  still one of the most common pain relievers more
  than 100 years later.

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Test Preparation
Reading Skills

• 7. The main reason willow bark has been used as a
  painkiller and fever treatment is because
• F. chemists can use it to make painkilling
  compounds.
• G. it contains elements that have painkilling
  effects.
• H. it contains compounds that have painkilling
  effects.
• I. no other painkillers were available long ago.
  

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Test Preparation
Reading Skills

• 7. The main reason willow bark has been used as a
  painkiller and fever treatment is because
• F. chemists can use it to make painkilling
  compounds.
• G. it contains elements that have painkilling
  effects.
• H. it contains compounds that have painkilling
  effects.
• I. no other painkillers were available long ago.
  

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Test Preparation
Reading Skills

• 8. Why is aspirin normally used as a painkiller
  instead of salicylic acid?
• A. Aspirin tends to cause less nausea.
• B. Aspirin is cheaper to make than salicylic
  acid.
• C. Only aspirin can be isolated from willow
  bark.
• D. Salicylic acid is less effective as a
  painkiller.

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Test Preparation
Reading Skills

• 8. Why is aspirin normally used as a painkiller
  instead of salicylic acid?
• A. Aspirin tends to cause less nausea.
• B. Aspirin is cheaper to make than salicylic
  acid.
• C. Only aspirin can be isolated from willow
  bark.
• D. Salicylic acid is less effective as a
  painkiller.

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Test Preparation
Interpreting Graphics

• The table and graph below show a relationship of
  direct
• proportionality between mass (grams) versus
  volume (cubic centimeters). Use it to answer
  questions 9 through 12.

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Test Preparation
Interpreting Graphics

• 9. Based on information in the table and the
  graph, what is the relationship between mass and
  volume of a sample of aluminum?
• F. no relationship
• G. a linear relationship
• H. an inverse relationship
• I. an exponential relationship

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Interpreting Graphics

• 9. Based on information in the table and the
  graph, what is the relationship between mass and
  volume of a sample of aluminum?
• F. no relationship
• G. a linear relationship
• H. an inverse relationship
• I. an exponential relationship

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TEST PREP
Interpreting Graphics

• 10. From the data provided, what is the density
  of aluminum?
• A. 0.37 g/cm3
• B. 1.0 g/cm3
• C. 2.0 g/cm3
• D. 2.7 g/cm3

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Test Preparation
Interpreting Graphics

• 10. From the data provided, what is the density
  of aluminum?
• A. 0.37 g/cm3
• B. 1.0 g/cm3
• C. 2.0 g/cm3
• D. 2.7 g/cm3

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Test Preparation
Interpreting Graphics

• 11. Someone gives you a metal cube that measures
  2.0 centimeters on each side and has a mass of
  27.5 grams. What can be deduced about the metal
  from this information and the table?
• F. It is not pure aluminum.
• G. It has more than one element.
• H. It does not contain any aluminum.
• I. It is a compound, not an element.

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Standardized Test Preparation
Chapter 1
Interpreting Graphics

• 11. Someone gives you a metal cube that measures
  2.0 centimeters on each side and has a mass of
  27.5 grams. What can be deduced about the metal
  from this information and the table?
• F. It is not pure aluminum.
• G. It has more than one element.
• H. It does not contain any aluminum.
• I. It is a compound, not an element.

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Test Preparation
Understanding Concepts

• 12. The density of nickel is 8.90 g/cm3. How
  could this information be applied, along with
  information from the graph, to determine which of
  two pieces of metal is aluminum, and which is
  nickel?

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Test Preparation
Understanding Concepts

• 12. The density of nickel is 8.90 g/cm3. How
  could this information be applied, along with
  information from the graph, to determine which of
  two pieces of metal is aluminum, and which is
  nickel?
• Answer From the table, you can calculate the
  density of aluminum. Aluminum is much less dense
  than nickel, so if the pieces of metal are the
  same size, the lighter one is aluminum.