Elements are the Building Blocks of Matter
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)
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)
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)
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)
Symbols and Jokes
Element Jokes and Puns
Question : Anyone know any jokes about sodium?
Answer:
Na
Please accept my apology !
 Sorry for making bad chemistry jokes
but all the good ones Argon !!!!!!
Let’s Get Serious… one more
Question to consider…
 What is the difference between Co and CO?
(hint look at the periodic table for help)
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 #
Copy into notebook (example)
# Protons (Electrons)
# Protons + Neutrons
Element - Atomic # and Mass #
Element – Atomic # and Mass#
Examples
New Element Discovered !!!!
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 !!!
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.
Mendeleev’s Periodic Table
There are a lot of gaps, but look at the horizontal rows (periods)
and compare to the current periodic table.
Current Periodic Table
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)
Periodic Table
 Table is made up (2) major groups (Metal and Non metals)
separated by a Ladder Shaped Line
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.
 Elements are grouped on the basis of similar characteristics
 (3) major groups of Elements are: Metals, non-metals and
Metalloids (semi- metals)
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
 Ductile: ability of a substance to be pulled or stretched.
 Malleable: ability of a substance to be bent or molded
into different shapes.
Color our Periodic Table
 Metals – Blue
Non- Metal – Red
 Metalloids (Semi-Metals)- circle them
Some other Special Groups within the Periodic Table
 Transition Metals - (tough metals)
- center of Periodic Table
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)
 (4)
Special Groups of Elements
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
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
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
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.
Noble Gas Joke
 Helium walks into a restaurant ,
 The waitress says "We don't serve noble gasses in
here."
 Helium doesn't react.
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.
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
Bohr – Rutherford Diagrams
 Need to review the Atom
 Protons
 Electrons
 Neutrons
 Energy Levels 2,8,8,18
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.
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.
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)
and electrons
Bohr- Rutherford Diagram
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
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
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-familiesvideo.htm