Quick
Review
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SPI 0807.9.9
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THE PRESENTATION
Periodic
Table

Periodic table
 A chart of all known chemical elements
 Shows all the different types of atoms
Purpose
 To quickly locate a variety of information about a
particular element
How is it organized




Organized into rows called periods
Organized into columns called groups (also called families)
Arranged in numerical order (by the atomic number)
Also arranged other ways (metals, nonmetals, metalloids, etc)
Notes
SPI 0807.9.9 Periodic Table
Groups/Families

Columns are called groups Groups are also called families
Group 1 is called the alkali metal family (see below)
Group 1=Alkali Metals
Alkali metals are the most
reactive
group/family!
Alkali
Metals:
Notice they are in group 1.
So they have one valence electron.
Their outer shells are not full.
Easily react with other elements. Why?
Notes
SPI 0807.9.9 Periodic Table
Groups/Families

Group 2 is called the alkali-earth metal family (see below)
Group 2=Alkali-Earth Metals
Alkali-earth
metals are
very reactive!
Alkali-Earth
Metals:
Notice they are in group 2.
So they have two valence electrons.
Their outer shells are not full.
Easily react with other elements. Why?
Notes
SPI 0807.9.9 Periodic Table
Groups/Families

Groups 3 to 12 are called the transition metals (see below)
Groups 3 to 12=Transition Metals
Transition Metals
Transition Metals (Lanthanides)
Transition Metals (Actinides)
Notes
SPI 0807.9.9 Periodic Table
Groups/Families
Group 17 is called the halogen family (see below)
Group 17=Halogens
Halogens are
very reactive!
Halogens:
(Flourine
is theare
most
reactive
Notice they
in group
17. non-metal)
So they have seven valence electrons.
Their outer shells are not full.
Easily react with other elements. Why?

Notes
SPI 0807.9.9 Periodic Table
Groups/Families

Group 18 is called the noble gas family (see below)
Group 18=Noble Gases
Noble
Noble gases
areGases:
non-reactive!
Notice they are in group 18.
So they have 8 valence electrons.
Their outer shells are completely full.
They do not react with other elements. Why?
Notes


Reactivity in Elements
Valence electrons are the key. (These are the electrons
in the outermost energy level.)
The number of valence electrons determines how and
if the element/atom will chemically react/bond
Note: Boron has three
total valence electrons
+x5
-
x6
-
-
-
Boron Atom
Notes
CLE 3221.3.1
Chemical Bonding
Reactivity in Elements
Electrons are located in shells
according to rules:
1) The 1st shell can hold up to two electrons
2) Other outer shells can hold up to 8 electrons.
Notes
CLE 3221.3.1
Chemical Bonding
Reactivity in Elements
Chemical Reactions/Chemical Bonding:
…elements/atoms react to fill their outer electron shells
2 Key Types of Chemical Bonds
1) Ionic bonds are…
…the transfer of electrons
2) Covalent bonds are…
…the sharing of electrons
IONIC BOND
bond formed by electron transfer
COVALENT BOND
bond formed by sharing of electrons
Notes