Element Families on the Periodic Table

Element Families
Members of element families share similar properties because they have the same outer electron orbital structure.

In chemistry, element families are groups of elements that share common properties. In fact, another name for an element family is an element group. Element families help distinguish element properties beyond those of metals, nonmetals, and metalloids.

Why Elements in Element Families Share Common Properties

The reason elements within a family display similar properties is because elements in a group have the same outermost electron orbital structure. While the atomic nucleus and other electrons contribute to individual element characteristics, it’s the outer electrons that participate in chemical reactions.

Elements in the same column are congeners. For example, chlorine and bromine are congeners of fluorine. Oxygen and polonium are another example congeners. In this case, these elements are quite different from one another, yet because of their similar electron structure, they still share some common properties.

Element Groups vs Element Families

An element group is a column of elements on the periodic table. There are 18 element groups, which appear on the periodic table as numbers listed above the element columns. For example, the first column is group 1, I, or IA, depending on the numbering system.

For the most part, element families and element groups are the same thing. But, families focus on element properties that are common between an element and those located below it on the periodic table. For example, group 16 corresponds to the oxygen group or chalcogens.

List of Element Families

Chemists group elements into either five or nine element families:

5 Element Families

The five element families combine similar element groups. So, even though there are numerous columns of transition metals on the periodic table, they all belong to the same family. The transition metals also include the lanthanides and actinides, which appear the main body of the table. Under this classification system, metals and metalloids transition between the other groups. So, this classification system does not include all of the elements of the periodic table.

  1. Alkali metals
  2. Alkaline earth metals
  3. Transition metals
  4. Halogens
  5. Noble gases

9 Element Families

The list of nine element families is more popular and more inclusive. Under this classification system, element families correspond to their periodic table column, which in turn reflects their typical number of valence electrons.

  1. Alkali Metals: Group 1 (IA) – 1 valence electron
  2. Alkaline Earth Metals: Group 2 (IIA) – 2 valence electrons
  3. Transition Metals: Groups 3-12 – d and f block metals have 2 valence electrons
  4. Boron Group or Earth Metals: Group 13 (IIIA) – 3 valence electrons
  5. Carbon Group or Tetrels: – Group 14 (IVA) – 4 valence electrons
  6. Nitrogen Group or Pnictogens: – Group 15 (VA) – 5 valence electrons
  7. Oxygen Group or Chalcogens: – Group 16 (VIA) – 6 valence electrons
  8. Halogens: – Group 17 (VIIA) – 7 valence electrons
  9. Noble Gases: – Group 18 (VIIIA) – 8 valence electrons

A Closer Look at the Element Families

Alkali Metals Family

Alkali Metal Element Group
Alkali metals have one valence electron.

The representative element of the alkali metals group is lithium, rather than hydrogen. This is because hydrogen is a gas at ordinary temperatures and pressures and behaves as a nonmetal. However, solid hydrogen behaves as an alkali metal.

  • Group 1 or IA
  • 1 valence electron
  • Soft metallic solids
  • Shiny, lustrous
  • High thermal and electrical conductivity
  • Low densities that increase with atomic mass
  • Relatively low melting points that decrease with atomic mass
  • Vigorous exothermic reaction with water to produce hydrogen gas and an alkali metal hydroxide solution
  • Ionize to lose their electron, so the ion has a +1 charge

Alkaline Earth Metals Family

Alkaline Earth Element Group
Members of the alkaline earth metals element family have two valence electrons.

Magnesium and calcium are examples of members of the alkaline earth element family. All of these elements are metals.

  • Group 2 or IIA
  • 2 valence electrons
  • Metallic solids, harder than the alkali metals
  • Shiny, lustrous metals
  • Easily oxidize
  • High thermal and electrical conductivity
  • More dense than the alkali metals
  • Higher melting points than alkali metals
  • Exothermic reaction with water, increasing as you move down the group; beryllium does not react with water; magnesium reacts only with steam
  • Ionize to lose their valence electrons, so the ion has a +2 charge

Transition Metals Element Family

Transition Metal Element Group
Sometimes lutetium and lawrencium are transition metals. Sometimes all of the lanthanide and actinide elements are in the family.

The transition metals are the largest family of elements. Transition metals include the entire middle of the periodic table. The lanthanides and actinides are special transition metals.

  • Groups 3-12
  • The d and f block metals have 2 valence electrons
  • Hard metallic solids
  • Shiny, lustrous
  • High thermal and electrical conductivity
  • Dense
  • High melting points
  • Large atoms exhibit a range of oxidation states

Boron Group or Earth Metal Element Family

Boron is the representative element of the boron family or earth metal family. The best-known member of the family is aluminum. These elements display a range of properties.

  • Group 13 or IIIA
  • Boron Group or Earth Metals
  • 3 valence electrons
  • Diverse properties, intermediate between those of metals and nonmetals

Carbon Group or Tetrels

The carbon family or tetrels have properties intermediate between metals and nonmetals. The name “tetrel” refers to the oxidation state or four valence electrons.

  • Group 14 or IVA
  • 4 valence electrons
  • Diverse properties, intermediate between those of metals and nonmetals
  • Best-known member: carbon, which commonly forms 4 bonds

Nitrogen Group or Pnictogens

Like the boron family and carbon family, members of the nitrogen family or pnictogens display a range of properties. The family includes nonmetals, metalloids, and metals.

  • Group 15 or VA
  • 5 valence electrons
  • Diverse properties, intermediate between those of metals and nonmetals
  • Best-known member: nitrogen

Oxygen Group or Chalcogens

Another name for the oxygen group is the chalcogen family.

  • Group 16 or VIA
  • 6 valence electrons
  • Diverse properties, changing from nonmetallic to metallic as you move down the family
  • Best-known member: oxygen

Halogen Element Family

Halogen Element Group
Members of the halogen element family have seven valence electrons or a usual oxidation state of -1.

The halogens are nonmetals, although tennessine might be more metallic.

  • Group 17 or VIIA
  • 7 valence electrons
  • Reactive nonmetals
  • Melting points and boiling points increase with increasing atomic number
  • High electron affinities
  • Elements change state moving down the family, with fluorine and chlorine existing as gases at room temperature while bromine is a liquid and iodine is a solid

Noble Gas Element Family

Noble Gas Element Group
The noble gas family is the last element family on the periodic table.

The noble gases are nonreactive nonmetals. Oganesson might be an exception in this regard, as it may be metallic. Examples of noble gases include helium and neon.

  • Group 18 or VIIIA
  • Noble Gases or Inert Gases
  • 8 valence electrons
  • Typically exist as monatomic gases, although these elements sometimes form compounds
  • Stable electron octet makes the element relatively inert under ordinary circumstances


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