Elements are the Building Blocks of Matter

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Chapter 2

• Elements are the Building Blocks of Matter

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Pure Substance

• A material that is made up of particles that are
  identical to each other. (all the same)
• Have their own set of properties
• - boiling point, density
• Two types of Pure Substances
• - Elements (Gold,
  Hydrogen)
• - Compounds (Pure Water,
  Salt)

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Elements

• pure substance with 1 type of atom
• cannot be broken down or separated into simpler
  substances.
• 109 different types of elements
• Are arranged in a Periodic Table according to
  their Atomic Number ( of protons in their
  Nucleus)

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Elements and Chemical Symbols

• In chemistry each Element has its own symbol
  which is used to show chemical formulas. NaCl
  
• Different ways to name Elements with symbols
• First Letter - Carbon - C
• First (2) Letters - Cobalt Co
• First and Third - Chromium Cr
• Latin or Non English - Iron Fe Ferrum
• Use same symbols around the world to communicate
  with different countries. (common language)

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Twenty Common elements
Symbol is the first letter in name Symbol is made from two letters in its name Symbol is based on non-English name
Hydrogen (H) Magnesium (Mg) Sodium (Na)
Carbon (C) Calcium (Ca) Potassium (K)
Nitrogen (N) Nickel (Ni) Iron (Fe)
Oxygen (O) Zinc (Zn) Copper (Cu)
Neon (Ne) Silver (Ag)
Helium (He) Gold (Au)
Chlorine (Cl) Mercury (Hg)
Silicon (Si) Lead (Pb)
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Symbols and Jokes
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Element Jokes and Puns

• Question Anyone know any jokes about sodium?
• Answer Na

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Please accept my apology !

• Sorry for making bad chemistry jokes but all the
  good ones Argon !!!!!!

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Lets Get Serious one more
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Question to consider

• What is the difference between Co and CO?
• (hint look at the periodic table for help)

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Atomic Number and Mass Number

• Each Element has (2) numbers written in the
  periodic table.
• Atomic Number - smaller number that tells you
  the number of Protons and Electrons in an
  atom
• Mass Number -bigger number that tells you how
  heavy the atom is (amu)
• Mass proton neutron

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Copy into notebook (example)

• 
  
• 
  Protons (Electrons)
• 
  
• 
  Protons Neutrons
  

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Element - Atomic and Mass
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Element Atomic and Mass
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Examples
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New Element Discovered !!!!
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Time for one more PUN ..

• Silver walks up to Gold in a party and says, "Au,
  get outta here!
• We would like to apologize for not adding more
  element jokes... but we only update them....
  Periodically !!!

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The First Periodic Table

• First designed by Dmitri Mendeleev (1869)
• First table consisted of only 63 elements.
• He left spaces for future elements that would be
  later discovered
• The table was later finished by later scientists.

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Mendeleevs Periodic Table
There are a lot of gaps, but look at the
horizontal rows (periods) and compare to the
current periodic table.
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Current Periodic Table
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Periodic Table (General Characteristics)

• Periodic table a chart that organizes all known
  elements according to their physical
  and chemical properties
• Arranged according to Atomic Number
• (Number of protons ) increases from (Left
  ---Right)
• Made up of (2) Major Groups
  Metals and Non-Metals
• Has (7) Rows - (Periods)
• Has (18) Columns (Groups) or (Families)

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Periodic Table

• Table is made up (2) major groups (Metal and Non
  metals) separated by a Ladder Shaped Line

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Periodic Table

• Remember that there are (3) Groups of elements in
  the Periodic Table 1) Metals , 2)
  Non- Metals and
  3) Metalloids or Semi Metals.

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• Elements are grouped on the basis of similar
  characteristics
• (3) major groups of Elements are Metals,
  non-metals and
• Metalloids (semi- metals)
• Ductile ability of a substance to be pulled or
  stretched.
• Malleable ability of a substance to be bent or
  molded into different shapes.

Metals Non-metals Metalloids
Shiny Ductile Malleable Conducts heat Conducts Electricity Dull Non-ductile Non-malleable Does not conduct heat Does not conduct electricity Shiny or dull Not ductile Not malleable Poor heat conductor May conduct electricity

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Color our Periodic Table

• Metals Blue Non- Metal Red
• Metalloids (Semi-Metals)- circle them

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Some other Special Groups within the Periodic
Table

• Transition Metals - (tough metals)
• -
  center of Periodic Table
• (4) Special Groups or Families (columns)
• Alkali Metals (Group 1) ( 1)
• Alkaline Earth Metals (Group 2) . (2)
• Halogens (Group 17) . or (Vii)
• Noble Gases (Group 18). (Viii) or (0)

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Special Groups of Elements
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Alkali Metals Family 1 (Group 1)

• Alkali Metals (Column 1)
• Very reactive and soft
• React with water, oxygen and other non-metals
• Low melting points
• Reactivity increases as you move down the column

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Alkaline Earth Metals Family 2 (Group 2)

• Alkaline Earth Metals (column 2)
• Less reactive than Alkali Metals
• Burn in air if heated, produce bright flames and
  used in fireworks
• Also reacts with water
• Reactivity increases as you move down the column

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Halogens- Family 17 (Group 17) (Group vii)

• Halogens (Column 17)
• Non-metals and highly reactive
• Fluorine and Chlorine are gases, Bromine is a
  liquid and Iodine is a solid
• Reactivity decreases as you move down the column
• Astatine is very rare and little is known about it

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Noble Gases- Family 18 (Group 18) (Group Viii or
0)

• Noble gases (column 18)
• Most stable and unreactive elements
• At room temperature they are colorless and
  odorless
• Some gases, like Argon and Neon are used in light
  fixtures
• Helium is lighter than air and is used in
  balloons.

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Noble Gas Joke

• Helium walks into a restaurant ,
• The waitress says "We don't serve noble gasses in
  here."
• Helium doesn't react.

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Another Chemistry Joke

• Two chemists go into a restaurant.
• The first one says "I think I'll have an H2O."
• The second one says "I think I'll have an H2O
  too"
• and he died.

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Locating Elements on the Periodic Table

• Make sure you can identify the relative position
  of elements on the periodic table
• What element is located at period 2, family 3?
• Boron

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Bohr Rutherford Diagrams

• Need to review the Atom
• Protons
• Electrons
• Neutrons
• Energy Levels 2,8,8,18

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Atomic Structure

• Bohr-Rutherford Diagram
• shows how many electrons are in each energy level
  (electron shell) surrounding the nucleus.
• Energy Level (or electron shell)
• the space around the nucleus in which the
  electrons may be found.
• Known as the 2-8-8-18 pattern
• The shell closest to center can hold 2 electrons
• The 2nd shell can hold up to 8 electrons
• The 3rd shell can hold up to 8 electrons
• The 4th shell can hold up to 18 electrons.

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How to Draw Bohr-Rutherford Models

• Step 1 Draw Nucleus
• Step 2 Put symbol, number of protons and number
  of neutrons in the Nucleus
• Step 3 Use the 2-8-8-18 pattern to fill the
  energy levels.

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Bohr Rutherford Diagram Example

• Diagram that includes (2) parts
• inside the nucleus (number of protons and
  neutrons)
• energy levels around the nucleus (electrons)
• Example (Sodium) Bohr- Rutherford
  Diagram
• and electrons

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How to Draw Bohr-Rutherford Models

• Step 1 Draw Nucleus
• Step 2 Put symbol, number of protons and number
  of neutrons in the Nucleus
• Step 3 Use the 2-8-8-18 pattern to fill the
  energy levels.
• NOTE the first energy level is filled first
  completely before going to the second,
  the second is filled
• before going to the third and
  so on.
• Draw Bohr Rutherford Diagram for Magnesium
• See page 62, figure 2.24

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Bohr-Rutherford

• Valence Energy Level
• the energy level that is the furthest from the
  nucleus
• Valence Electrons
• Electrons that are furthest away from the
  nucleus.
• They occupy the valence energy level

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Patterns Observed Using Energy Level Diagrams

• Elements in the same family have the same number
  of electrons in their valence energy level
• Period number indicates the number of energy
  levels
• The valence energy level structure determines how
  one element will react with another. Group 1 and
  Group 17 (Vii)
• If the valence level is full, then it is
  difficult to react (look at Noble gases)
• Website to show the similar properties of
  elements in families
• http//videos.howstuffworks.com/hsw/5793-periodic-
  table-families-video.htm