Elements and the Periodic
Table
Chapter 5
5.1 - Journal
1.
Take out your homework
2.
Color in the Periodic Table given to you and color it
in according to the following LIST. Use your book,
too!
Use a different color for each of the items below.








Alkali Metals
Alkaline Earth Metals
Transition Metals
Metalloids
Nonmetals
Halogens
Noble Gases
Other metals
5.1 – Journal
1.
Check your Periodic Table
5.1 - Organizing the Elements
MENDELEEV’S ORDER

Dmitri Mendeleev

Trying to organize the 63 known elements so they
were easier to understand
5.1 - Organizing the Elements
MENDELEEV’S ORDER: Didn’t yet know about
protons, neutrons and electrons, ONLY MASS..
What could he do?
5.1 - Organizing the Elements
MENDELEEV’S ORDER: Increasing Atomic Mass

Elements with similar properties were put in
the same column
5.1 - Organizing the Elements

Named “Periodic Table” because properties
repeated ‘periodically’ from row to row.

Like keys on a keyboard (octaves)
5.2 – The Modern Periodic Table
The Periodic Law

Once protons were discovered, what were
elements organized by?
Increasing Atomic Number.

Properties ARE STILL grouped by column.
So, Properties STILL repeat periodically (within a row).
5.2 – The Modern Periodic Table

Like Cards in a deck:
In the Modern table a PERIOD = a ROW.

How many PERIODS are there?
7
PERIODS = ROWS

How many ELEMENTS are in PERIODS 1, 2, and 3?
What does this remind you of?
Numbers of electrons in each ENERGY LEVEL


a
COLUMN = a GROUP
 ELEMENTS
within a GROUP have
similar PROPERTIES.
COLUMNS = GROUPS
Therefore, properties repeat
PREDICTABLY and PERIODICALLY.
 THIS IS CALLED PERIODIC LAW.

5.2 – The Modern Periodic Table
Example
Group (Family 1) – Alkali Metals
What is similar?
5.2 – The Modern Periodic Table
There are 4 important pieces of information for
each element
Atomic number
Element symbol
Element name
Atomic mass
5.2 – The Modern Periodic Table - Journal
1. What happens to properties
when you move from left to
right across the table?
2. What type of elements are in
yellow? In green? In blue?
3. What is the definition of a
“metalloid”?
4. What type of elements are in
the “B” columns?
5. List the names of all of the “A”
groups (families).
6. What is an important fact
about the Actinide series?
5.2 – The Modern Periodic Table
HOW CAN WE CLASSIFY ELEMENTS?
2.
State: solid, liquid, gas
Natural & manmade: (91 of the first 92 are
natural)
3.
METALS, NONMETALS & METALLOIDS
1.
5.2 – The Modern Periodic Table
Classified by Properties
What happens to properties when you move from left to right across the
table?
5.3 – Representative Groups
Elements in a group have SIMILAR (not
identical) PROPERTIES because they have the
same number of valence electrons
5.3 – Representative Groups
ALKALI METALS (group 1):
Single valence electron
 EXTREMELY REACTIVE
 Reactivity increases from
top to bottom

It is not a metal, but Hydrogen is
grouped here. Why?
5.3 – Representative Groups
ALKALINE EARTH METALS (group 2):


TWO valence electrons
Less reactive than group 1
5.3 – Representative Groups
BORON FAMILY (group 3A):

THREE valence electrons
FYI- Aluminum is the most
abundant metal in Earth’s crust

5.3 – Representative Groups
CARBON FAMILY (group 4A):

FOUR valence electrons

FYI- Except for water, most
compounds in your body contain
Carbon.
5.3 – Representative Groups
NITROGEN FAMILY (group 5A):

FIVE valence electrons

FYI- Nitrogen and Phosphorous are
used to make fertilizers.
5.3 – Representative Groups
OXYGEN FAMILY (group 6A):

SIX valence electrons

FYI- Oxygen is the most abundant
nonmetal in Earth’s crust, and
Ozone is another form of oxygen.
5.3 – Representative Groups
THE HALOGENS (group 7A):




SEVEN valence electrons
EXTREMELY REACTIVE
Reactivity increases from bottom to
top
FYI- Halogen means “salt former”.
5.3 – Representative Groups
THE NOBLE GASES (group 8A):



EIGHT valence electrons
INERT (don’t react easily)
FYI- make “neon” lights when a
current is passed thru them.