Families of the Periodic Table
Notes
The Periodic Table
The periodic table is arranged into groups and periods. It is also arranged by
metals, non-metals, and metalloids.
Groups
Groups are also called families. These are the vertical columns (up and down).
Elements in groups have similar properties. They have the same number of
electrons in their outer energy level. The group number (e.g. 1A) is the number of
valence electrons.
Periods
Horizontal rows are called periods. Elements in the same period have the same
number of energy levels. The row number is the number of energy levels.
Metals
Elements located on the left of the “staircase” of the periodic table are metals.
Properties of metals:
 Usually solid at room temperature
 Conduct heat and electricity well
 Have luster – reflect light well
 Are malleable – can be hammered or rolled into sheets
 Are ductile – can be drawn into wires
Non-metals
Located on the right side of the “staircase”
Properties of non-metals:
 Usually gases or brittle solids at room temp.
 Are NOT:
o Malleable
o Ductile
o Lustrous
o Good conductors (they are good insulators)
Metalloids
They are the elements that are on either side of the “staircase”, with the
exception of Aluminum (a metal). They exhibit properties of both metals and
non-metals. In particular, they are partial conductors of electricity making them
semi-conductors.
In summary:
Things that you can tell about elements by looking at the periodic table:
1) Name
2) Symbol
3) # of Protons, Neutrons & Electrons
4) Number of energy levels
5) Number of electrons in the outer energy level
6) Metals, Non-metals, or metalloids
Families of the Periodic Table
The main families (groups) are:
1) The Alkali Metals
2) The Alkaline Earth Metals
3) The Halogens
4) The Noble Gases
5) The Transition elements
The Alkali Metals (Group 1A)
 Softer and more reactive than other metals
 Highly reactive with Oxygen and water
 Do not occur naturally in the elemental form
 Combine (bond) readily with other elements. Why?
 Because they have only 1 valence electron
Alkaline Earth Metals (Group 2A)
 Not found naturally in elemental form
 They are denser, harder, and have a higher melting point than alkali
metals.
 Two valence electrons
Halogens (Group 7B)
 Form salts when gaining 1 electron from a metal (ex. sodium chloride).
 Bond well with the Alkali Metals. Why?
 Because it needs ONE electron to fill its outer shell
Noble Gases (Group 8B)
 Exist as isolated, stable atoms
 This is because they completely fill their outer energy level.
 Do not bond with other elements (there are some rare exceptions, usually
only occurs in laboratories)
Transition Elements (Groups 3 – 12)
 Metals
 Found in the middle of the Periodic Table


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Often occur in nature as uncombined elements
Typically form colored compounds
Include the inner transitions metals
Inner Transition Elements
 Metals
 Located at the bottom of the chart
 Contain 2 main groups:
o The Lanthanides (Rare-earth elements)
o The Actinides
 Located “off” the chart to allow the Periodic Table to fit better.
 Typically exist in combined forms with other elements, or, they are
formed in laboratories.
 These elements are radioactive