Matter

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Matter

• What is matter?
• How are interactions between matter and energy
  exhibited in nature?

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Quick Review of Terms.

• Chemistry is the study of matter and how it
  changes.
• Matter is anything that has mass and takes up
  space.
• Elements are substances that cannot be broken
  down into simpler substances.
• Atoms are the smallest particles that still have
  the properties of elements.

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Review continued..

• Compounds are substances made up of atoms of more
  than one element bound together.
• Molecules are the smallest units of a substance
  that still exhibit all of the properties of the
  substance.

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What is a chemical formula?

• The chemical symbols and numbers indicating the
  atoms contained in the basic unit of the
  substance.
• C6 H12 O6
• This formula represents a molecule of sugar.

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Did you know?

• A pure substance is matter with a fixed
  composition and definite properties.
• A mixture is a combination of more than one pure
  substance.
• A homogeneous mixture looks the same throughout,
  like salt and water.
• A heterogeneous mixture is incompletely mixed,
  like flour and water.

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Liquids.

• Gasoline is a liquid mixture- a homogeneous
  mixture of about 100 different compounds in
  various quantities. Because the compounds are
  miscible, gasoline looks like a pure substance
  even though it isnt.

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Miscible

• Describes two or more liquids that are able to
  dissolve into each other in various proportions.
• Immiscible describes two or more liquids that do
  not mix into each other.

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Can a gas mix with a liquid?

• It can! Have you ever had a carbonated soft
  drink?
• Carbonated soft drinks are not allowed in this
  class!

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Matter and Energy

• The Kinetic theory of matter
• All matter is made up of atoms and molecules that
  act like tiny particles.
• These tiny particles are always in motion. The
  higher the temperature, the faster the particles
  move.
• At the same temperature, more massive (heavier)
  particles move slower than less massive(lighter)
  particles.

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Remember the three states of matter?

• Solids have a rigid structure.
• Liquids take the shape of their container.
• Gasses exert pressure.
• Ps there is a fourth, Plasma, however it does
  not exist on earth, it is the most abundant state
  of matter in the universe.

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Energy

• Energy is the ability to move or change matter.
• Energy added to water will cause a change in
  state from solid to liquid, and liquid to gas.
• Energy removed from water will cause a change
  from gas to liquid, and liquid to solid.

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Energy is transferred in all changes of state.

• Evaporation, condensation and sublimation.
• Evaporation liquid to gas
• Condensation gas to liquid
• Sublimation solid to gas

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LAW of Conservation of MASS.

• Mass cannot be created or destroyed.

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LAW of conservation of ENERGY.

• Energy cannot be created or destroyed.

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Properties of Matter

• Chemical property, the way a substance reacts
  with others to form new substances.
• Reactivity- the ability of a substance to combine
  with another substance.
• Physical properties, a characteristic of a
  substance that can be observed or measured
  without changing the composition of the substance.

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Physical properties

• Melting point, the temperature at which a solid
  becomes a liquid.
• Boiling point, the temperature at which a liquid
  becomes a gas below the surface.
• Shape, color, odor, and texture are physical
  properties.

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Density

• The mass per unit volume of a substance.
• Formula Dm/V
• Buoyancy the force with which a more dense fluid
  pushes a less dense substance upward.

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Changes

• Chemical change, occurs when a substance changes
  composition by forming one or more new
  substances. Changes is composition.
• Physical change, a change in physical form or
  properties of a substance that occurs without a
  change in composition. Dissolving is a physical
  change.

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Atoms and the Periodic Table

• Atomic Structure Review

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Atomic Structure

• Daltons Theory
• Every element is made up of tiny, unique
  particles called atoms that cannot be subdivided.
• Atoms of the same element are exactly alike
• Atoms of different elements can join to form
  molecules.

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Atoms have a structure.

• Nucleus, the center of an atom, contains protons
  and neutrons.
• Proton, a positively charged particle.
• Neutron, a neutral charged subatomic particle.

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Particles in Orbit around the Nucleus.

• Electron, a tiny negatively charged subatomic
  particle moving around the nucleus in an orbit.

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The Orbitals.

• Orbital, the region in an atom where there is a
  high probability of finding electrons.

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More about orbitals..

• Electrons usually occupy the lowest energy levels
  available in an atom, and within the lowest
  energy level electrons will occupy the orbitals
  with the lowest energy.

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The Valence Shell

• An electron in the outermost level is called a
  valence electron.

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How are the elements organized?

• Periodic law- Properties of elements tend to
  change in a regular pattern when elements are
  arranged in order of increasing atomic number, or
  number of protons in their atoms.

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Periods, Families and position.

• The periodic table is arranged in horizontal rows
  called periods. Think about an English sentence,
  you write from left to right and can end it with
  a period.
• A column in the table is a family (group) and
  these elements have similar properties.

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Its Ionic, think about it.

• When you add or remove electrons from an element
  you are left with a charge. This is called
  ionization.
• If you add an electron- the atom ends up more
  negative and the charge is this is called an
  anion.
• If you lose an electron the atom ends up more
  positive , and this is called a cation.

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The atomic number.

• The atomic number is the number of protons in the
  atom, and since all atoms are naturally neutral
  that means that the number represents the
  neutrons and the electrons as well.

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The mass number

• The atomic mass of an atom is calculated by
  adding the mass of the protons and neutrons in
  the nucleus.
• WHY dont we add the number of electrons into
  this calculation since they have mass as well?

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Just when you thought you had it, you find out
about isotopes!

• Isotopes- when an atom gains or loses one or more
  neutrons. The chemical properties remain the
  same, the atomic mass changes.
• Mass number- The total number of protons and
  neutrons in the nucleus.
• Calculating the number of neutrons in an atom,
  give it a try!!

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Your turn..

• Carbon-14
• Nitrogen-15
• Sulfur-35
• Calcium-45
• Iodine-131
• Oxygen-18
• Tritium

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Families of Elements

• First look at the periodic table as consisting of
  metals and nonmetals.
• Now look at the first group(1) located beneath
  Hydrogen. These are the Alkali Metals. These are
  highly reactive!

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Families of Elements

• Look to the right of the alkali metals.
• The group(2) elements are known as the
  Alkaline-earth metals. These are less reactive
  metals that contain 2 valence electrons, and
  usually react to form 2 cations.

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Families of Elements

• Look to the right of the alkaline-earth metals.
• This section begins the transition metals.
  (Group3-12) These are much less reactive, but
  they can lose electrons to form cations. Most of
  these elements have complex arrangements of
  electrons.

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Families of Elements

• Look at the right side of the periodic table
  after the transition metals.
• This section begins the nonmetals. Group 13 has
  only one nonmetal in it and that is Boron. Below
  it are metals referred to as other metals.

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Families of Elements

• Look to the right again.
• Group 14 has three nonmetals beginning with
  Carbon and ending with Germanium, the remaining
  elements below are other metals.

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Families of Elements

• Look to the right again.
• Group 15 contains 4 nonmetals beginning with
  Nitrogen and ending with Antimony. The remaining
  element is Bismuth and is an other metal.

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Families of Elements

• Look to the right.
• The 16th group is made up of mostly nonmetals
  beginning with Oxygen and extending through
  Tellurium. The remaining elements are Other
  metals.

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Families of Elements

• The 17th group is known as the Halogens. These
  are toxic to living organisms.

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Families of Elements

• The 18th group is known as the Noble Gases. Neon
  lights for example. These are inert and are used
  for many purposes from giving planes lift to
  filling light bulbs. The term inert is used when
  describing these gasses.

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The Semiconductors

• The semiconductors are located to the right of
  the transition metals on the periodic table and
  are intermediate conductors of heat and
  electricity. Silicon , Boron, Germanium, Arsenic,
  Antimony, Tellurium.