The Periodic Table

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Be able to read and understand the block
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The Periodic Table
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Why is the Periodic Table important to me?

• The periodic table is the most useful tool to a
  chemist.
• You get to use it on almost every test.
• It organizes lots of information about all the
  known elements.

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Pre-Periodic Table Chemistry

• was a mess!!!
• No organization of elements.
• Imagine going to a grocery store with no
  organization!!
• Difficult to find information.
• Chemistry didnt make sense.

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Dmitri Mendeleev Father of the Table

• Russian Chemist
• Mendeleev was the first scientist to notice the
  relationship between the elements
• Published the first version of the periodic table
  in 1869
• Arranged elements according to increasing atomic
  mass
• His periodic table had gaps

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Mendeleevs Table
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Mendeleevs Published Periodic Table of Elements
Why do you think there are question marks here?
Image taken from http//www.chemsoc.org/networks/
learnnet/periodictable/post16/develop/mendeleev.ht
m
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Mendeleevs Predictions

• Although Mendeleevs Periodic Table of Elements
  had missing elements or gaps, he was able to
  predict the characteristics of these missing
  elements because of Periodic Law.

Ekasilicon
Germanium
Notice how Mendeleevs predictions (orange
column) were very accurate when compared to
Germaniums actual characteristics (green column)
Date Predicted 1871 Date Discovered 1886
Atomic Mass 72 Atomic Mass 72.6
Density 5.5 g/cm3 Density 5.47 g/cm3
Bonding Power 4 Bonding Power 4
Color Dark Gray Color Grayish White
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Dmitri Mendeleev Father of the Table

• 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 mass to
  keep similar reacting elements together.

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

http//www.youtube.com/watch?vfPnwBITSmgU http//
www.youtube.com/watch?vcvRcUeWjBu0
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Henry Moseley (1887-1915)

• Made improvements to Mendeleevs Periodic Table
• Moseley later discovered that the periodic nature
  of the elements was associated with atomic
  number, not atomic mass
• Arranged elements by atomic number instead of
  mass
• Realized that there were still undiscovered
  elements

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The Current Periodic Table

• Mendeleev wasnt too far off.
• Henry Moseley rearranged the periodic table and
  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 are
  labeled from 1 to 18.

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GroupsHeres Where the Periodic Table Gets
Useful!!

• 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,
  number of electrons on the last energy level.
• They will react with other elements in similar
  ways.

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Valence electrons-How many electrons are in the
outermost shell?
Si
Ge
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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 have names rather than numbers. (Just
  like your family has a common last name.)

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Families of the Periodic Table
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Whats in a square?

• Different periodic tables can include various
  bits of information, but usually
• atomic number 1
• Symbol H
• atomic mass 1.0007
• number of valence electrons
• state of matter at room temperature.

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Representative Elements

• Groups 1-2 13-18
• 1 Alkali Metals
• 2 Alkaline Earth Metals
• 13 The Boron Family
• 14 The Carbon Group
• 15 The Nitrogen Group
• 16 The Oxygen Group
• 17 The Halogens
• 18 The Noble Gases

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Transition Elements

• Groups 3-12
• Transition Elements
• All transition elements are metals.
• Group 11 (The Coinage Metals)
• The Lanthanides
• The Actinides

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• https//www.youtube.com/watch?vOairdijvADE
• Summary

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• End of first Powerpoint

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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

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Alkali Metals

• 1st column on the periodic table (Group 1) not
  including hydrogen.
• Very reactive metals, always combined with
  something else in nature (like in salt).
• Soft enough to cut with a butter knife

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Alkali Metals

• http//www.open.edu/openlearn/science-maths-techno
  logy/science/chemistry/alkali-metals

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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)

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Transition Metals

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

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Boron Family

• Elements in group 13
• Aluminum metal was once rare and expensive, not a
  disposable metal.

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Carbon Family

• Elements in group 14
• Contains elements important to life and
  computers.
• Carbon is the basis for an entire branch of
  chemistry.
• Silicon and Germanium are important
  semiconductors.

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Nitrogen Family

• Elements in group 15
• Nitrogen makes up over ¾ of the atmosphere.
• Nitrogen and phosphorus are both important in
  living things.
• Most of the worlds nitrogen is not available to
  living things.
• The red stuff on the tip of matches is phosphorus.

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Oxygen Family or Chalcogens

• Elements in group 16
• Oxygen is necessary for respiration.
• Many things that stink, contain sulfur (rotten
  eggs, garlic, skunks,etc.)

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Halogens

• Means salt former
• Elements in group 17
• Very reactive, volatile, diatomic, nonmetals
• Always found combined with other elements in
  nature .
• Used as disinfectants and to strengthen teeth.

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The Noble Gases
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The Noble Gases

• Elements in group 18
• VERY unreactive, monatomic gases
• Used in lighted neon signs
• Used in blimps to fix the Hindenberg problem.
• Have a full valence shell.

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• http//www.open.edu/openlearn/science-maths-techno
  logy/science/chemistry/noble-gases

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• http//www.youtube.com/watch?vUy0m7jnyv6U
• Meet the Elements
• http//www.youtube.com/watch?v-wu0LixSBpk

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http//laughingsquid.com/the-periodic-table-of-ele
mental-discoveries-by-country/
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Families on the Periodic Table

• Elements on the periodic table can be grouped
  into families bases on their chemical properties.
• Each family has a specific name to differentiate
  it from the other families in the periodic table.
• Elements in each family
• react differently with
• other elements.

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Periods

• Each row is called a period

• The elements in each period have the same number
  of shells

1st Period 1 Shell
2nd Period 2 Shells
3rd Period 3 Shells
4th Period 4 Shells
www.chem4kids.com
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Groups
Group 8 8 electrons
Group 1 1 electron
Except for He, it has 2 electrons
Group 2 2 electrons

• Each column is called a group

3, 4, 5, 6, 7

• Each element in a group has the same number of
  electrons in their outer orbital, also known as
  shells.

• The electrons in the outer shell are called
  valence electrons

www.chem4kids.com
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Periodic table song

• http//www.youtube.com/watch?vzUDDiWtFtEMfeature
  youtube_gdata_player
• "Hunting the Elements" NOVA special http//www.you
  tube.com/watch?vct3ubD47gTE

(2012) NOVA show Hunting The Elements   http//www
.pbs.org/wgbh/nova/physics/hunting-elements.html
lecture series with Peter Wothers is really,
really good The Modern Alchemist Air Ri
Channel  It covers something we all experience
with every breat
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