Topic 5- The Periodic Table
Periodic Law: The properties of the elements are periodic
functions of their atomic numbers
The modern periodic table is not arranged by increasing atomic
mass, but rather by increasing atomic number.
Each element is represented by symbols, and each symbol has one,
two, or three letters. The first letter is capitalized, and any other
letters present are lower case. Symbols are assigned by an
organization known as IUPAC after agreement on the name of a
newly discovered element.
Arrangement of the periodic table
The horizontal rows of the table are called periods. Elements on
the same row will have same number of principal energy level
(orbital).
The vertical columns of the periodic table are called groups, or
families. Elements in the same column will have same number of
valence electrons (outer most electrons). The number of valence
electrons for each element is shown as the last number in the
electron configuration.
Types of elements:
General properties of metals
 All metals are solids, except mercury (Hg), which is
liquid.
 Metals are malleable (bend into different shape)
 Metals are ductile, (pulled into a wire)
 Metals have luster, (shiny)
 Metals are good conductors of heat and electricity
 Metals have low ionization energy, and low
electronegativity values
 Metals tend to lose electrons to form positive ions with
smaller radii
General properties of nonmetals
 Nonmetals are not malleable or ductile, they tend to be
brittle in the solid phase
 Nonmetals have high ionization energy and high
electronegativity values
 Nonmetals are poor conductors of heat and electricity
 Nonmetals tend to gain electrons to become negative ions
with radii larger than their atoms
Transition elements:
 Elements of group 3 through 12
 Transition elements have multiple oxidation states
 Release Color when reacted in solution
Noble Gases:
 Group 18 elements
 Unreactive, inactive, inert
 Octet Rule - Have 8 electrons on the outer most energy
level, (valence electrons) (orbital)
Alkali metals
 Group 1 elements
 Most reactive metals
 Like to lose 1 electron and becomes +1 ion
 Francium (Fr) is the most reactive metal
Alkaline earth metals
 Group 2 elements
 Second most Reactive metals
 Like to lose 2 electrons and becomes +2 ion
Halogens
 Group 17 elements
 Most reactive nonmetals
 Like to gain 1 electron and becomes -1 ion, called halides
 Fluorine (F) is the most reactive nonmetal
Metals: Left side of the steps
Nonmetal: Right side of the steps
Metalloid: B, Si, Ge, As, Sb, and Te
Gas molecules: H, N, O, F, Cl, He, Ne, Ar, Kr, Xe, and Rn
Liquid elements: Hg (metal) and Br (nonmetal)
Properties of elements:
As you move from left to right of each period (row)
1. Ionization energy increases
2. Electronegativity increases
3. Atomic radii decreases
As you move from top to bottom of each group (column)
1. Ionization energy decreases
2. Electronegativity decreases
3. Atomic radii increases