Carbon Family of Elements

Element Group 14 - Carbon Family Facts

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One way to classify elements is by family. A family consists of a homologous element with atoms having the same number of valence electrons and thus similar chemical properties. Examples of element families are the nitrogen family, oxygen family, and carbon family.

Key Takeaways: Carbon Family of Elements

  • The carbon family consists of the elements carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), and flerovium (Fl).
  • Atoms of elements in this group have four valence electrons.
  • The carbon family is also known as the carbon group, group 14, or the tetrels.
  • Elements in this family are of key importance for semiconductor technology.

What Is the Carbon Family?

The carbon family is element group 14 of the periodic table. The carbon family consists of five elements: carbon, silicon, germanium, tin, and lead. It is likely that element 114, flerovium, will also behave in some respects as a member of the family. In other words, the group consists of carbon and the elements directly below it on the periodic table. The carbon family is located very nearly in the middle of the periodic table, with nonmetals to its right and metals to its left.

The carbon family is also called the carbon group, group 14, or group IV. At one time, this family was called the tetrels or tetragens because the elements belonged to group IV or as a reference to the four valence electrons of atoms of these elements. The family is also called the crystallogens.

Carbon Family Properties

Here are some facts about the carbon family:

  • Carbon family elements contain atoms that have 4 electrons in their outer energy level. Two of these electrons are in the s subshell, while 2 are in the p subshell. Only carbon has the s2 outer configuration, which accounts for some of the differences between carbon and other elements in the family.
  • As you move down the periodic table in the carbon family, the atomic radius and ionic radius increase while electronegativity and ionization energy decrease. Atom size increases moving down the group because an additional electron shell is added.
  • Element density increases moving down the group.
  • The carbon family consists of one nonmetal (carbon), two metalloids (silicon and germanium), and two metals (tin and lead). In other words, the elements gain metallicity moving down the group.
  • These elements are found in a wide variety of compounds. Carbon is the only element in the group that can be found pure in nature.
  • The carbon family elements have widely variable physical and chemical properties.
  • Overall, the carbon family elements are stable and tend to be fairly unreactive.
  • The elements tend to form covalent compounds, though tin and lead also form ionic compounds.
  • Except for lead, all of the carbon family elements exist as different forms or allotropes. Carbon, for example, occurs in diamond, graphite, fullerene, and amorphous carbon allotropes. Tin occurs as white tin, gray tin, and rhombic tin. Lead is only found as a dense blue-gray metal.
  • Group 14 (carbon family) elements have much higher melting points and boiling points than the group 13 elements. Melting and boiling points in the carbon family tend to decrease moving down the group, mainly because atomic forces within the larger molecules are not as strong. Lead, for example, has such a low melting point that it's easily liquefied by a flame. This makes it useful as a base for solder.

Uses of Carbon Family Elements and Compounds

The carbon family elements are important in daily life and in industry. Carbon is the basis for organic life. Its allotrope graphite is used in pencils and rockets. Living organisms, proteins, plastics, food, and organic building materials all contain carbon. Silicones, which are silicon compounds, are used to make lubricants and for vacuum pumps. Silicon is used as its oxide to make glass. Germanium and silicon are important semiconductors. Tin and lead are used in alloys and to make pigments.

Carbon Family - Group 14 - Element Facts

C Si Ge Sn Pb
melting point (°C) 3500 (diamond) 1410 937.4 231.88 327.502
boiling point (°C) 4827 2355 2830 2260 1740
density (g/cm3) 3.51 (diamond) 2.33 5.323 7.28 11.343
ionization energy (kJ/mol) 1086 787 762 709 716
atomic radius (pm) 77 118 122 140 175
ionic radius (pm) 260 (C4-) -- -- 118 (Sn2+) 119 (Pb2+)
usual oxidation number +3, -4 +4 +2, +4 +2, +4 +2, +3
hardness (Mohs) 10 (diamond) 6.5 6.0 1.5 1.5
crystal structure cubic (diamond) cubic cubic tetragonal fcc


  • Holt, Rinehart and Winston. "Modern Chemistry (South Carolina)." Harcourt Education, 2009.
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Your Citation
Helmenstine, Anne Marie, Ph.D. "Carbon Family of Elements." ThoughtCo, Aug. 28, 2020, Helmenstine, Anne Marie, Ph.D. (2020, August 28). Carbon Family of Elements. Retrieved from Helmenstine, Anne Marie, Ph.D. "Carbon Family of Elements." ThoughtCo. (accessed March 26, 2023).

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