Elements and the Periodic Table

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• Elements and the Periodic Table

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Classifying Matter

• Classification is arranging items into groups or
  categories according to some criteria.
• The act of classifying creates a pattern that
  helps you recognize and understand things such as
  the behavior of fish, chemicals, or any matter in
  your surroundings.

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Classifying Matter

• Matter is usually defined as anything that has
  mass and occupies space.
• Matter occurs in 4 basic states or phases
• Solid
• Liquid
• Gas
• Plasma

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SOLIDS

• Particles in solids are close together,
  vibrating.
• A solid has a definite shape.
• A solid has a definite volume.

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LIQUIDS

• Particles in liquids have more energy than in a
  solid.
• Particles are close together, flowing around
  each other.
• A liquid takes the shape of its container.
• A liquid has a definite volume.
• A substance that is somewhere between a solid
  and a liquid is a suspension. Check out this
  colloid suspension http//www.science-house.org/
  CO2/activities/polymer/oobleck.html

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• Particles in gases have more energy than a
  liquid and are not close together, but they can
  collide.
• A gas will fill a container. The larger the
  container, the more gas expands to fill it.
• A gas has no definite shape or volume because of
  this.

GASES
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PLASMA

• Particles in plasma have the greatest energy of
  all states of matter.
• Plasma occurs when the temperature is between
  1000 degrees C and 1,000,000,000 degrees C.
• Some examples of plasma are the charged air
  around lightning and stars, including our own
  sun.

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More about PLASMA

• As a gas is heated, electrons begin to leave the
  atoms, resulting in the presence of free
  electrons
• At very high temperatures, such as those present
  in stars, it is assumed that essentially all
  electrons are "free," and that a very high-energy
  plasma is nothing but bare nuclei swimming in a
  sea of electrons.
• Plasma is believed to be the most common state
  of matter in the universe.
• http//www.youtube.com/watch?vUjqEx4ttUDY--plasma
  cutter
• http//www.youtube.com/watch?vlRU43nbVaz8--stars
  compared to planets

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http//www.harcourtschool.com/activity/states_of_m
atter/
Gas
Liquid
Solid
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The greater the thermal energy of the object,
the faster the particles move.
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• The particles at the
• upper left show the
• arrangement of
• particles in ice.
• The particles at the
• lower right show
• what happens to
• particles as ice melts.
• A container of water will expand as it freezes
  due to the shape water particles take
  (hexagonal) when changing into the solid state.
• This shape takes up more room than liquid water
  particlesand there is empty space in the middle
  of the crystal shape.

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From Solid to Liquid

• The melting point of a substance is the point at
  which the particles have gained enough energy so
  as to fall out of order and begin to flow around
  one another.
• The melting point of water at sea level is 32 F
  (0 C).
• The melting point of aluminum at sea level is
  1220.58 F (660.32 C).

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From Liquid to Solid

• The freezing point of a substance is the point at
  which the particles have lost enough energy so as
  to fall into order and stop the flow of particles
  around one another.
• The freezing point and melting point of a
  particular substance is the same.
• It depends on whether energy is being added or
  taken away.
• The freezing point of water at sea level is 32 F
  (0 C).
• The freezing point of aluminum at sea level is
  1220.58 F (660.32 C).

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From Liquid to Gas

• When particles have gained enough energy so that
  they move away from each other with empty space
  between, they have reached the point of
  vaporization.
• Substances that vaporize throughout are said to
  have reached the boiling point.
• Substances that vaporize on the surface are said
  to have evaporated.
• The boiling point of water at sea level is 212 F
  (100 C).
• The boiling point of aluminum is 4566 F (2519
  C) at sea level.

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MIXTURES AND PURE SUBSTANCES

• A mixture has unlike parts and a composition that
  varies from sample to sample. (Ex. Halloween
  candy, salt and pepper)
• A heterogeneous mixture has physically distinct
  parts with different properties. (Ex. vegetable
  soup, nuts and bolts)
• A homogeneous mixture is the same throughout the
  sample. (Ex. Kool-Aid, salt water, bronze, air)
• Pure substances are substances with a fixed
  composition. (Ex. water alone, salt alone, iron
  alone, carbon dioxide alone)

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Pure Substances

• A compound is a pure substance that can be broken
  down by a chemical change into simpler
  substances.
• Water, H20, is a pure substance that can be
  broken down into 2 hydrogen atoms and one oxygen
  atom.
• An element is a pure substance which cannot be
  broken down into anything simpler by either
  physical or chemical means.
• Hydrogenor any other element on the periodic
  table is an element that, under normal
  circumstances, cannot be broken down further
  without being changed into energy.
• Hindenburg Disaster http//www.youtube.com/watch
  ?vJSuR2IgnimA
• Blimp filled with hydrogen
• 35 of 97 On board died
• Hydrogen Bomb http//www.youtube.com/watch?vNNcQ
  X033V_M

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Ways Stuff Can Change

• A physical change is a change that does not alter
  the identity of the matter.
• Ice melting is a physical change. It is still
  water, no matter what state of matter it is in.
• Tearing paper is physical. It is still paper.
• A chemical change is a change that does alter the
  identity of the matter.
• Breaking apart H20 is a chemical change. It is
  no longer water when the molecule is broken
  apart. It becomes two gaseshydrogen and oxygen.
• http//www.periodictable.com/Stories/001.1/
• Burning sugarC6H1206breaks it down into carbon,
  water, and carbon dioxide, which is NOT the same.

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• A graphic organizer for matter

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A
B

• Sugar (A) is a pure substance that can be easily
  broken into 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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ANSWER THIS!

• Water is a
• heterogeneous mixture
• homogeneous mixture
• pure substance
• Compound
• pure substance and compound

Answer E
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• Elements

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First, A Little History . . .

• The Ancient Idea of Elements
• Traditionally, early Greeks considered that there
  were four classical elements earth, air, fire,
  and water.

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First, A Little History . . . continued

• The Ancient Idea of Elements
• Later, around 1667, it was thought there was the
  existence of, in addition to the classical four
  elements of the Greeks, an additional fire-like
  element called phlogiston that was contained
  within combustible (burnable) or rustable bodies,
  and released during combustion or rusting .
• The theory was an attempt to explain oxidation
  processes such as combustion and the rusting of
  metals.

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First, A Little History . . . continued

• What the heck is phlogiston?
• The phlogiston theory from 1667 viewed phlogiston
  as a component of matter.
• The burning or rusting of a material was
  considered to be the escaping of phlogiston from
  the matter.
• If a material did not burn or rust, it was
  considered to contain no phlogiston.

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• Discovery of Modern Elements
• In the late 1700s, Antoine Lavoisier of France
  suggested that burning was actually a chemical
  combination with oxygen.
• Lavoisier realized that there needed to be a new
  concept of elements, compounds, and chemical
  change.
• We now know that there are 89 naturally-occurring
  elements and at least 23 short-lived and
  artificially prepared elements.
• The elements of the periodic table are believed
  to be all the elements that exist in the
  universe!
• Click here to see how we know
  http//spiff.rit.edu/classes/phys301/lectures/spec
  tra/spec_proper_orientation.gif

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• Names of Elements
• The first 103 elements have internationally
  accepted names, which can come from
• 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 is
  made up of just seven elements.

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Atomic Theory
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Democritusthe Greek Dude

• Lived from 480 BC to 370 BC
• Was a Greek philosopher
• He created a theory that argued that there are
  various basic elements which always existed but
  can be rearranged into many different forms.
• Quote By convention there is sweet, by
  convention there is bitterness, by convention hot
  and cold, by convention color but in reality
  there are only atoms and the void.
• Named the parts of matter atomos, which means
  uncuttable.

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John Dalton

• Lived 6 September 1766 27 July 1844
• Was a schoolteacher and scientist in England
• Thought atoms were tiny solid masses
• Dalton first published his theories on atoms in
  1808 in a small book titled A New System of
  Chemical Philosophy. The book had an enormous
  influence on the development of both chemistry
  and physics.

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John Daltons Atomic Theory

• Elements are made of tiny particles called atoms.
  
• All atoms of a given element are identical.
• The atoms of a given element are different from
  those of any other element.
• Atoms of one element can combine with atoms of
  other elements to form chemical compounds a
  given compound always has the same relative
  numbers of types of atoms.
• Atoms cannot be created, divided into smaller
  particles, nor destroyed in the chemical process
  a chemical reaction simply changes the way atoms
  are grouped together.

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Daltons Laws

• The Law of Constant Composition
• Any given compound always consists of the same
  atoms and the same ratio of atoms. For example,
  water always consists of oxygen and hydrogen
  atoms, and it is always 89 percent oxygen by
  mass and 11 percent hydrogen by mass.
• The Law of Conservation of Mass
• The total mass of materials before and after a
  chemical
• reaction must be the same. For example, if we
  combine
• 89 grams of oxygen with 11 grams of hydrogen
  under
• the appropriate conditions, 100 grams of water
  will be
• producedno more and no less.

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Making Sense of the Elements
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Pre-Periodic Table Chemistry

• was a mess!!!
• No organization of elements
• Difficult to find information
• Chemistry didnt make sense.

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Why Is the Periodic Table Important?

• The periodic table is the most useful tool to a
  chemist.
• It organizes lots of information about all the
  known elements.

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• Dmitri Mendeleev
• Born in 1834 in Siberia, the youngest of 14
  children, died in 1907
• Gave us a functional scheme with which to
  classify elements

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Dmitri Mendeleev Father of the Periodic Table

• HOW HIS WORKED
• Put elements in rows by increasing atomic weight.
• Put elements in columns by the way they reacted.

• SOME PROBLEMS
• He left blank spaces for what he said were
  undiscovered elements. (Turned out he was
  right!)
• He broke the pattern of increasing atomic weight
  to keep similar reacting elements together.

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Mendeleevs Periodic Table
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The Modern Periodic Table
http//www.chemicalelements.com/elements/ba.html
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The Current Periodic Table

• Mendeleev wasnt too far off.
• Now the elements are put in rows by increasing
  ATOMIC NUMBER!!
• The horizontal rows are called periods and are
  labeled from 1 to 7.
• The vertical columns are called groups or
  families and are labeled from 1 to 18.

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Understanding the TableChemical Elements

• The atomic number is the number of protons in
  the nucleus.
• The atomic mass or weight is the protons plus
  the neutrons in the nucleus (total weight of the
  nucleus).
• Electrons have so very little mass that they
  are not included in the atomic mass.
• The number of protons always remains the same
  for each element. Example Carbon ALWAYS has 6
  protons.

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Isotopes

• Atoms of the same element can have different
  numbers of neutrons the different possible
  versions of each element are called isotopes.

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Groups Columns on the Periodic Table

• Elements in the same group have similar chemical
  and physical properties!!
• (Mendeleev did that on purpose.)

• Why??
• They have the same number of valence electrons.
• They will form the same kinds of ions.

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Nitrogen
Valence electrons are the electrons in the
outside energy level of an atom.
Valence Electrons
Valence Electrons
http//www.chemicalelements.com/elements/n.html
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Forming Ions
-
Chlorine (Cl )
Sodium (Na )

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Families on the Periodic Table

• Columns are also grouped into families.
• Families may be one column, or several columns
  put together.
• Families often have names rather than numbers.
  (Just like your family has a common last name.)
• www.periodicvideos.com

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Hydrogen

• Hydrogen belongs to a family of its own.
• Hydrogen is a diatomic, reactive gas.
• Hydrogen was involved in the explosion of the
  Hindenberg.
• Hydrogen is promising as an alternative fuel
  source for automobiles
• Hydrogen only needs 2 electrons to fill up its
  valence shell.

http//www.youtube.com/watch?vF54rqDh2mWA
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Alkali Metals

• The alkali family is found in the first column of
  the periodic table.
• Atoms of the alkali metals have a single electron
  in their outermost level, in other words, 1
  valence electron.
• They are shiny, have the consistency of clay, and
  are easily cut with a knife.

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Alkali Metals

• They are the most reactive metals.
• They react violently with water.
• Alkali metals are never found as free elements in
  nature. They are always bonded with another
  element.
• http//www.youtube.com/watch?vYvSkXd_VVYkNR1fe
  aturefvwp

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What Makes an Element Reactive?

• An incomplete valence electron level.
• All atoms (except hydrogen helium) want to
  have 8 electrons in their very outermost energy
  level (This is called the rule of octet.)
• Atoms bond until this level is complete. Atoms
  with few valence electrons lose them during
  bonding.
• Atoms with 5, 6 or 7 valence electrons gain
  electrons during bonding.

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Alkaline Earth Metals

• Second column on the periodic table (Group 2)
• Reactive metals that are always combined with
  nonmetals in nature
• Several of these elements are important mineral
  nutrients (such as Mg and Ca).
• Many are used in the production of fireworks.

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Transition Metals

• Elements in groups
• 3-12
• Less reactive harder metals
• Includes metals used in jewelry and construction
• Metals in this family are used as metals.

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Transition Metals

• The compounds of transition metals are usually
  brightly colored and are often used to color
  paints.
• Transition elements have 1 or 2 valence
  electrons, which they lose when they form bonds
  with other atoms. Some transition elements can
  lose electrons in their next-to-outermost level.

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Transition Metals

• Transition elements have properties similar to
  one another and to other metals, but their
  properties do not fit in with those of any other
  family.
• Many transition metals combine chemically with
  oxygen to form compounds called oxides.

Iron oxideruston iron
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Boron Family

• Elements in group 13 have 3 valence electrons.
• Includes metals and one metalloidBoron.
• Aluminum, the most abundant metal in Earths
  crust, was once considered rare and expensive--
  not a disposable metal.

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Carbon Family

• Elements in group 14 have 4 valence electrons.
• Contains elements important to life--and
  computers.
• Carbon is the basis for an entire branch of
  chemistry (organic chemistry).
• Silicon and Germanium are important
  semiconductors used in computer chips.

• This family includes a non-metal (carbon),
  metalloids, and metals.
• Carbon has many forms, some of which are
• Radioactive
• Diamond
• Graphite
• Buckminsterfullerene

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Nitrogen Family

• Elements in group 15 have 5 valence electrons.
• They tend to share electrons when they bond.
• This family includes non-metals, metalloids, and
  metals.
• Nitrogen makes up over 75 of the atmosphere.
• Nitrogen and phosphorus are both important in
  living things.
• The red stuff on the tip of matches is
  phosphorus.

• http//www.youtube.com/watch?vrPbE2KSPxuUfeature
  related
• http//www.youtube.com/watch?v1DxLwZhTj0A

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Oxygen Family

• Elements in group 16 have
• 6 valence electrons.
• Oxygen is necessary for
• respiration.
• Many things that stink,
• contain sulfur (rotten eggs,
• garlic, skunks, etc.).
• Most elements in this family
• share electrons when forming compounds.
• Oxygen is the most abundant element in the
  earths crust. It is extremely active and
  combines with almost all elements.

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Halogens

• Halogens are in group 17 and have 7 valence
  electrons, which explains why they are the most
  active non-metals. Always found combined with
  other elements in nature.
• They are very reactive diatomic nonmetals.
• Used as disinfectants and to strengthen teeth
• Halogen atoms only need to gain 1 electron to
  fill their outermost energy level.
• They react with alkali metals to form salts.

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The Noble Gases
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The Noble Gases

• Elements in group 18 have 8 valence electrons.
• They are VERY unreactive, monatomic gases.
• Also called inert, meaning unreactive
• Used in lighted neon signs
• Used in blimps to fix the Hindenberg problem
• Have a full valence shell
• All the noble gases are found in small amounts in
  the earth's atmosphere.

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Rare Earth Elements

• The thirty rare earth elements make up the
  lanthanide (row 1) and actinide (row 2) series.
• One element of the lanthanide series and most of
  the elements in the actinide series are called
  trans-uranium, which means synthetic or man-made.
• Magnets made from rare earth elements are some of
  the strongest.

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Metals, Nonmetals, Metalloids

• Metal Elements that are usually solids at room
  temperature.
• Most elements are metals.
• Non-Metal Elements in the upper right corner of
  the periodic table.
• Their chemical and physical properties are
  different from metals.
• Metalloid Elements that share some properties
  with metals, some with nonmetals.
• They can conduct electricity better than
  nonmetals, but not as good as some metals.

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What Can a Row (Period) Tell You?

• The row an element is in tells how many energy
  levels it has.
• There are seven rows, so the maximum number of
  energy levels is 7!

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More Information on Ionic Bonds

• When two or more atoms combine, the compound as a
  whole is neutral because the sum of the ions is
  zero.
• When an atom or molecule gain or loses an
  electron it becomes an ion.
• A cation has lost an electron and has a positive
  charge.
• An anion has gained an electron and has a
  negative charge.
• Therefore, a cation with a 1 and an anion with a
  -1 add up to a ZERO charge.

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Remember Salt
-
Chlorine (Cl )
Sodium (Na )

Cation
Anion
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Another Ionic Bond

• Magnesium chloride
• MgCl2 is the chemical formula.
• Magnesium is in Group 2Alkaline Earth Metalsso
  it has 2 valence electrons to give up.
• Chlorine, in Group 17the Halogensneeds only one
  valence electron, so it takes 2 chlorines to
  neutralize Magnesium.

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Electron Configuration of MgCl2
-1
X
2
-1
X
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Electron Dot Diagrams

• Electron dot diagrams are another way to show
  bonding using just the valence electrons.
• Sodium and all others in the Alkali Metals group
  would have one dot.
• Na

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Using Dot Diagrams to Show Bonding
Na Cl -

• Na Cl

• Sodium has one valence electron.
• Chlorine has 7 valence electrons.
• When they bond, you can see how chlorine now
  has a stable outer shell.
• You also know sodium is now stable since it got
  rid of its single valence electron.

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Sharing Electrons

• Another kind of bond is called a covalent bond.
• Covalent means sharing valence electrons.
• The shared bond results in a molecule.
• Covalent bonds form between nonmetallic elements.
• Many covalent compounds are liquids or gases at
  room temperature.

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Single Covalent Bonds

• Here is an example of a single covalent bond
  where only one electron from each element is
  shared.
• H H O H O
• H

• Now each element has a stable number of
• valence electrons by sharing!

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Unequal Sharing

• Some molecules do not share electrons evenly.
• Water is a good example.
• When 2 or more different-sized atoms bond, the
  larger atom usually pulls a little bit more on
  the shared electrons, giving that end of the
  molecule a more negative charge.
• The other end of the molecule will have a more
  positive charge.

-
H O H

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Unequal Sharing

• This unequal sharing is called a polar bond.
• The molecule now has a NORTH pole and a SOUTH
  polelike a magnet.
• Water molecules behave like magnets because of
  this.
• They will attract more water molecules and will
  bead up or hold together to form a skin.

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Polar Bonds
Water bug standing on water
Water beading up on a car
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More on Covalent Bonds

• Heres an example of a diatom
• N N N N

• Each nitrogen from Group 15 has 5
• valence electrons, meaning each needs 3 more
  to be stable.
• They each share 3 electrons in order to become
• stable. So, in this case it is a TRIPLE bond
  (sharing 3 electrons each.
• Nitrogen shares evenly. This is a nonpolar bond.

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Oxidation Numbers

• Oxidation numbers of an element are the positive
  or negative numbers (ions) that indicate how many
  electrons an atom gains, loses, or shares to
  become stable.
• Calcium in group 2 has an oxidation number of 2.
• Fluorine in group 17 has an oxidation number of
  1- (it needs one electron to be stable).
• Therefore, it will take two fluorines to deal
  with
• the two electrons calcium has to offer.
• The chemical formula will then be CaF2.

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Why Does it form CaF2?

• Ca F

F
Ca F

• Calcium has 2 valence
• electrons to give away.
• Fluorine needs only one of
• those. Therefore, 2 fluorines
• are needed to bond with calcium.
• Is this an ionic or covalent bond?

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Periodic Table Link

• http//www.periodicvideos.com/