Chapter One: Matter and Change

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Chapter One Matter and Change

• In this Chapter
• Branches of Chemistry and types of Research.
• Molecules, atoms and compounds.
• Types of properties of matter.
• Classification of Matter
• Types of Elements on the Periodic Table
• Basic structure of the Periodic Table

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Chemistry is a Physical Science

• Chemistry is the study of the composition,
  structure, and properties of matter and the
  changes that matter undergoes.
• Chemistry is a physical science which focuses on
  non-living things.
• Instruments are routinely used in chemistry
  to extend our ability to observe and make
  measurements.

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Six Branches of Chemistry

• Organic Chemistry The study of most
  carbon-containing compounds.(C H O N)
• Inorganic Chemistry the study of all substances
  not classified as organic, mainly compounds that
  do NOT contain carbon.
• Physical Chemistry the study of the properties,
  changes, and relationships between energy and
  matter.
• Analytical Chemistry the identification of the
  components and composition of materials.
• Biochemistry the study of substances and
  processes occurring in living things.
• Theoretical Chemistry the use of mathematics and
  computers to design and predict the properties of
  new compounds.

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Types of Research

• Basic or pure research The purpose of this type
  of research is carried out to increase our
  knowledge of the how and why a specific reaction
  occurs.
• Applied research This research is carried out to
  solve a direct specific problem of chemistry.
• Technological Development This type of research
  uses chemistry to produce new chemicals and
  products to improve life.

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DEFINITIONS

• Mass is the measure of the amount of matter
  present in a substance.
• Inertia is a property of all matter, which
  resists a change in motion and is based on the
  amount of matter present.
• Weight is a measure of the earth's gravitational
  attraction for matter.
• Matter is anything that occupies space(volume)
  and has mass.
• A chemical is any substance that has a definite
  composition and properties associated with its
  composition.
• ENERGY is the ability to cause change or the
  ability to do work.

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Weight and Mass

• The more matter in the object, the stronger the
  force exerted on it and the further it is pulled
  down or weight. Scientists make a distinction
  between weight and mass.
• MASS is the measure of the quantity or amount of
  matter an object contains or has in it.
• The interchangeable use of the terms mass and
  weight is common and ordinarily it causes no
  problems.
• If the masses of two objects are the same, they
  have equal weights while in the same location.

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Two classes of Energy

• KINETIC energy The energy of an object in motion
  and depends on the mass of the object and its
  velocity or speed. KE ½ mv2
• POTENTIAL energy The energy that an object has
  because of it's position, or composition. PE
  mgh
• Potential energy can be thought of as stored
  energy, waiting to be released by chemical or
  mechanical means into kinetic energy.

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Examples of Potential Energy

• The energy in gasoline is chemical potential
  energy.
• Water held behind a dam has gravitational
  potential energy.
• A book being held up three feet from the floor
  has stored energy.
• A clock spring has potential energy, which is
  slowly converted to kinetic energy.
• Potential energy can be thought of as positonal
  energy.

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Fundamental Law of the Conservation of Matter

• The LAW OF CONSERVATION OF MATTER states Matter
  cannot be either created or destroyed in ordinary
  chemical or physical changes.
• In chemistry, this is the most basic and
  fundamental law and all chemical reactions must
  account for the total matter that undergoes a
  reaction.

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Fundamental Law of the Conservation of Energy

• The LAW OF CONSERVATION OF ENERGY states Energy
  can be converted from, one form to another, but
  it cannot be created or destroyed in ordinary
  chemical or physical changes.
• This is NOT true for nuclear reactions, where
  mass is converted to energy.

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Properties and Changes of Matter

• Properties are characteristics that enable
  scientists to distinguish one kind of matter from
  another.
• Physical properties can be observed or measured
  without changing or altering the identity of a
  material.
• Physical properties of pure elements and
  compounds are constant or unchanging.
• Any change in a property of matter that does not
  result in a change in identity is called a
  Physical Change.
• Changes of state are changes between the gaseous,
  liquid, and solid state and are physical changes.

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Two types of physical properties

• EXTENSIVE physical properties that depend on the
  amount of matter present, such as mass, length
  and volume.
• INTENSIVE physical properties do not depend on
  the amount of matter present, such as melting and
  boiling density, color, crystalline arrangement.
• Examples of physical changes
• 1.    Melting
• 2.    Boiling
• 3.    Freezing
• 4.    Liquefaction of a gas.

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STATES of MATTER

• SOLID state the form of matter that has a
  definite volume and resists a change in shape.
• LIQUID state the form of matter that has a
  definite volume, but no definite shape.
• GASEOUS state the form of matter that has
  neither a definite shape nor volume.

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Chemical Properties

• A CHEMICAL change refers to the ability of a
  substance to undergo a change that alters the
  identity of a substance.
• A CHEMICAL change or REACTION is any change in
  which one or more substances are converted into
  different substances that have different
  identifying properties.
• REACTANTS in a chemical reaction are the
  materials, which interact with each other.
• PRODUCTS of a chemical reaction are the new
  materials or substances produced by the
  interaction of the reactants.

Sodium metal chlorine gas
sodium chloride
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Indicators of a Chemical Reaction

• Production of Heat and Light.
• Production of a Gas.
• Formation of a precipitate, which is a solid
  which appears after two solutions have been mixed
  together.

In many chemical reactions, more than one
indicator may be evidenced.
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Energy and changes in matter

• Chemical and physical changes in matter can cause
  energy changes.
• Energy may be either released or absorbed. Most
  chemical reactions release energy.
• In physical processes, the addition or release of
  heat by a substance sauses a phase changes in the
  substance.

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Two Processes of energy changes

• EXOTHERMIC changes A process in which materials
  are undergoing physical and/or chemical changes
  that result in heat being released into the
  surrounding environment.
• ENDOTHERMIC - a process in which materials are
  undergoing physical and/or chemical changes that
  result in heat being absorbed.

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Classification of matter

• MIXTURES which are a combination of 2 or more
  kinds of matter, with each material still having
  its own composition and properties.
• TWO TYPES OF MIXTURES
• HETEROGENOUS mixture - mixtures in which the
  composition and properties of the ingredients are
  NOT uniformly dispersed.
• HOMOGENOUS mixture - mixtures in which the
  composition and properties of the ingredients are
  uniformly dispersed.

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A Special type of Homogenous Mixture

• SOLUTIONS are mixtures that are homogenous, such
  as, salt dissolved in water, or a piece of iron
  or brass.
• The air we breathe is a mixture of the gases of
  nitrogen, oxygen, carbon dioxide, and water
  vapor.

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Pure Substances

• A PURE SUBSTANCE is a homogenous sample of matter
  that has the same composition and properties and
  is classified either as a compound or an element.
  
• Elements cannot be separated into smaller parts
  without destroying their identity and are pure
  substances.
• Compounds can be broken to elements, but this
  alters their chemical and physical properties,
  yet they are pure substances as well.

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Differences between Mixtures and Pure Substances

• Every sample of a given pure substance has
  exactly the same chemical and physical
  properties.
• Every sample of a given pure substance has
  exactly the same composition or makeup.
• Pure Substances cannot be separated into other
  substances without changing its identity.

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Types of PURE SUBSTANCES

• ELEMENTS - a substance that cannot be decomposed
  or broken down into simpler substances by
  ordinary chemical means.
• COMPOUNDS - a substance of definite composition
  that can be decomposed or broken down into two or
  more simpler substances by ordinary chemical
  means.
• Elements are the atoms found on the periodic
  table or chart.

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Laboratory Chemicals and Purity

• There are seven grades of chemical purity of
  chemical elements and compounds.

Primary Standard reagents ACS (American Chemical
Society- specified reagents) USP (U.S.
Pharmacopoeia standards) CP (chemically pure
purer than technical grade) NF (National
Formulary specifications) FCC (Fodd Chemical Code
specification) Technical (industrial chemicals)
Highest purity
Lowest purity
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Law of Definite Composition

• The Law of Definite Composition states A
  chemical compound contains the same elements in
  exactly the same proportions by mass regardless
  of the size or amount of the compound.
• In water, H2O this means that there is always a
  ratio by mass of one gram hydrogen to eight grams
  of oxygen.
• This means the ratio of the mass of the elements
  in a specific compound will NEVER vary.

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The PERIODIC TABLE

• Chemical elements are the building blocks of all
  matter and there are to date 116 different
  elements.
• Of these elements, only 92 are naturally
  occurring in the world around us.
• The periodic table is a chart that organizes
  elements based on their atomic and chemical
  characteristics.
• The location of an element on the periodic chart
  determines whether a substance is a metal,
  nonmetal or metalloid.

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2 major divisions of the Periodic Table

• Groups or families the vertical (up/down)
  columns of elements, which have similar chemical
  properties. There are 18 major groups on the
  periodic table.
• Periods the horizontal (across) rows of elements
  and are numbered from 1 to 7.
• There are other divisions on the periodic chart,
  and they will be discussed later in the year.

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4 TYPES OF ELEMENTS

• METALS Good conductors of heat and electricity
  Have a luster and are generally solids, Malleable
  and ductile approximately 75 of all elements.
• NONMETALS Poor conductors of heat and
  electricity Gases, liquids, or solids, dull and
  brittle when solids approximately 15 of all
  elements.
• METALLOIDS semiconductors of electricity
  Solids, having the characteristics of both metals
  and nonmetals approximately 10 of all elements.
  
• NOBLE or INERT GASES elements that are
  essentially non-reactive to other elements not
  found in large amounts in nature approximately
  5 of all elements