CHEMISTRY

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CHEMISTRY

• MATTER
• AND
• STATES OF MATTER

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Hold on to your hats! Its going to be an
exciting ride!
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CHEMISTRY

• The study of the composition, structure, and
  properties of matter and the changes that matter
  undergoes
• Includes chemical and physical properties, how
  things interact, and what they are made of.

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WHAT IS MATTER

• Matter Anything that has mass and takes up
  space
• Composition of Matter
• Atoms
• Elements
• Molecules
• Compounds

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Composition of Matter

• Element (Pure Substance) A substance that
  cannot be broken down into simpler substances by
  chemical means
• Examples Oxygen, Aluminum, Carbon
• Located in the periodic table

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• Names of Elements
• The first 103 elements have internationally
  accepted names, which are derived from
• The compound or substance in which the element
  was discovered
• An unusual or identifying property of the element
• Places, cities, and countries
• Famous scientists
• Greek mythology
• Astronomical objects.

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• The elements of aluminum, Iron, Oxygen, and
  Silicon make up about 88 percent of the earth's
  solid surface. Water on the surface and in the
  air as clouds and fog is made up of hydrogen and
  oxygen. The air is 99 percent nitrogen and
  oxygen. Hydrogen, oxygen, and carbon make up 97
  percent of a person. Thus almost everything you
  see in this picture us made up of just six
  elements.

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Composition of Matter

• Atoms The smallest unit of an element that
  maintains the properties of that element
• The particles that make up all matter

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Composition of Matter

• Compounds A substance made of two or more
  different elements that are chemically combined
• Example Nylon is a combination of carbon,
  hydrogen, nitrogen,and oxygen atoms
• Example Composition of air

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• Compounds have unique properties different from
  the elements themselves
• Example Sodium is very reactive (reacts with
  water violently)
• Example Chlorine is a very toxic gas (has been
  used as chemical warfare gas)
• Sodium and Chlorine combined make TABLE SALTthe
  properties change when elements become compounds.

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Sodium and Chlorine Table Salt
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Composition of Matter

• Molecule The smallest unit of a substance that
  keeps all of the physical and chemical properties
  of that substance.
• Example one water molecule carries all the
  properties of a glass full of water

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Chemical Formula

• A combination of chemical symbols and numbers to
  represent a substance
• Shows the number of atoms of each element in a
  compound
• Ex Table Sugar C12H22O11
• 12 Carbon atoms, 22 Hydrogen atoms, 11 Oxygen
  atoms

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Substances and Mixtures

• A pure substance is a kind of matter that cannot
  be separated into other kinds of matter by any
  physical process.
• Pure Substances are Elements or compounds
• A mixture is a material that can be separated by
  physical means into two or more substances.
• Homogeneous or Heterogeneous

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Pure Substances and Mixtures Chart
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• Get two types of mixtures
• A homogeneous mixture is a mixture that is
  uniform in its properties throughout given
  samples.
• Often called a SOLUTION
• A heterogeneous mixture is a mixture that
  consists of physicallly distinct parts, each with
  different properties.

Heterogeneous
Homogeneous
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2 Types Heterogeneous Mixtures

• 1. Suspension particles can separate out
• EX Orange juice with pulp
• 2. Colloid particles are able to separate light
  and cannot be separated by ordinary filters.
• EX milk, Jello, fog

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Figure 3.4 Table salt is stirred into water
(left), forming a homogeneous mixture called a
solution (right)
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Figure 3.5 Sand and water do not mix to form a
uniform mixture
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Separation of Mixtures

• Examples to separate homogeneous mixtures
• Distillation
• - Chromatography

• Examples to separate heterogeneous mixtures
• - Magnetic
• Filtration

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• Sugar (A) is a compound that can be easily
  decomposed to simpler substances by heating. (B)
  One of the simpler substances is the black
  element carbon, which cannot be further
  decomposed by chemical or physical means.

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Basic Distillation Setup
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Separation of Mixtures by Paper Chromatography
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Figure 3.9 Separation of a sand-saltwater mixture
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States of Matter
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Classifications of Matter
Solid ? rigid, definite volume and shape. Liquid
? relatively incompressible fluid, definite
volume, takes shape of container. Gas ?
easily compressible fluid, no fixed volume or
shape.
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Disorder Some space Particles closer together
Order Particles fixed in position
Total disorder Lots of empty space
Gas Liquid
Solid
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Plasma

• Fourth state of matter
• Most common in the universe
• Does not have a definite shape
• Particles can conduct electric current
• Electric and magnetic fields affect plasma
• Natural plasma is found in lightning, fire, and
  aurora borealis

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Energy and Changes in State

• An introduction through music

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Kinetic Theory of Matter

• All matter is made of atoms and molecules that
  act like tiny particles
• All of these tiny particles are in MOTION.
• The higher the temperature, the faster the
  particles move.
• Heavy particles move slower than light particles
  at the same temperature.

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Thermal Energy and Expansion

• Most matter expands when it gets hot and
  contracts when it cools (exception water)
• Thermal Energy The total kinetic energy of the
  particles that make up the object.
• Objects with a lot of kinetic energy have more
  thermal energy
• Temperature is a measure of average kinetic
  energy.
• Objects with more motion in their particles will
  have a higher temperature

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Expansion Joints
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Changes of State

• Evaporation and Condensation
• Freezing and Melting
• Sublimation and Deposition

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State Changes
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• Evaporation Liquid changes to a gas
• Water to steam
• sweating
• Condensation Gas changes to a liquid
• Steam to water
• Water droplets on the side of your glass

• Heat of Vaporization the amount of energy
  needed to change a material from a liquid to a gas

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• Melting Solid changes to a liquid
• Ice to water
• Heat of Fusion the amount of energy needed to
  change a material from the solid state to the
  liquid state
• Freezing Liquid changes to a solid
• Water to ice

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• Sublimation Solid changes to a gas skipping the
  liquid state
• Dry ice
• Deposition Gas changes to a solid skipping the
  liquid state

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Transfer of Heat Energy

• Heat energy always moves from the warmer object
  to the colder object.
• Caused by the Kinetic Theory of Matter
• Three Ways
• Conduction
• Convection
• Radiation

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Conduction

• The transfer of heat energy by touch
• Ex touching the desk will transfer heat energy
  from your hand to the desk.

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Convection

• The transfer of heat energy by motion of
  particles.
• The warmer particles rise and push colder
  particles downthe cycle continues and causes a
  current.
• Ex boiling water

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Radiation

• The transfer of heat through light.

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Properties of Matter

• Physical and Chemical

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Physical Properties

• Physical Property any characteristic of a
  material that you can observe without changing
  the substances that make up the material
• Easily observed and measurable
• Includes Shape, size, color, mass, volume,
  density, temperature, melting point, boiling
  point, state of matter

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Chemical Property

• A characteristic of a substance that indicates it
  can change chemically
• Not as easy to observe
• Includes flammability, reactivity
• Example Steel combined with oxygen can lead to
  rust

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Physical Changes

• A physical change is a change in the form of
  matter but not in its chemical identity. Example
  
• - Dissolution of salt.
• - Distillation
• - Breaking pencil in two
• - Cutting hair
• Physical changes help to separate mixtures.

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Chemical Changes

• A chemical change or chemical reaction is a
  change in which one or more kinds of matter are
  transformed into a new kind of matter or several
  new kinds of matter.
• Cannot be reversed by physical changes
• Example
• The rusting of iron.
• Digesting food
• Rotting fruit
• Rusting steel
• Burning gasoline

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Chemical Changes (cont)

• Chemical changes can be detected by such things
  as odor or color
• Chemical changes form new substances that have
  new properties
• Example baking a cake

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Law of Conservation of Mass

• Matter is not created or destroyed during a
  chemical change
• The mass of all substances before a chemical
  change equals the mass of all substances after
  the chemical change

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