Group 14: Carbon Family

Generally, the group 14 elements are known as the carbon family. This group elements Carbon (C), Silicon (Si), Germanium (Ge), Tin (Sn), Lead (Pb) and Flerovium (Fl). These elements are classified as metals, metalloids, and nonmetals. They are also classified as amorphous and crystalline. They are widely distributed in the Earth and can be found in air and in organic compounds. These elements act as catalysts. The Group 14 elements are mostly nonmetals (Jones, 2011).

 

1. Electronic configuration

General electronic configuration of group 14 is ns2 np2. While the electronic configuration of group 14 members is as follows (Richardson, et al., 2015).

 

C [6] 1s2 2s2 2p2 or [He] 2s2 2p2
Si [14] 1s2 2s2 2p6 3s2 3p2 or [Ne] 3s2 3p2
Ge [32] 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2 or [Ar] 3d10 4s2 4p2
Sn [50] 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p2 or [Kr] 5s2 4d10 5p2
Pb [82] 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p2 or [Xe] 6s2 4f14 5d10 6p2
Fl [114] 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p2 or [Rn] 7s2 5f14 6d10 7p2

 

2. Characteristics of Group 14 elements

 

2.1. Oxidation state of Group 14 elements

• Unlike group 13, group 14 elements are not electropositive. The oxidation state of group 14 elements is generally +2 or +4. The number of valence electrons possessed by an element determines the oxidation state it may take. These are the elements found in group 14. When compared to the +4 oxidized state, the +2 oxidative state has a higher degree of stability. The idle pairing phenomenon is what’s thought to be responsible for it. The higher the oxidation state, the less stable it is.
• The +2 oxidation state is more prominent in group 14 elements such as tin and lead. These elements form divalent compounds
• Aside from their +2 oxidation state, group 14 elements also exhibit other oxidation states such as +4 and -2. As the group descends, the stability of the +4 oxidation state increases. Because there are just more atoms now than there were before.

 

2.1. Inert pair effect

• The inert pairing case illustrates how s-orbital electrons are uninterested in forming bonds. This causes the formation of ions with a lower oxidation number than is expected. This effect is observed in lead and is also known in lead chemistry.
• The inert pair effect increases the stability of the +2 oxidation state. However, the effect is different for covalent bonds. This is because in the case of covalent bonds, the s-orbital electrons are not allowed to participate in the bonding. The inert pair effect is observed in the group 14 elements, especially lead. The inert pair effect is not present in C, but it is present in the lighter elements of group 14. The inert pair effect is due to the outer electronic configuration of the ion being filled with an s-orbital subshell.

 

3. Anomalous behavior of Carbon

• Carbon has a number of unique properties. These properties include the ability to form multiple bonds, high electronegativity, and catenation. However, carbon is also anomalous. Therefore, it exhibits a behaviors distinct than the rest of its grouping. It shows an anomalous behavior because it lacks d-orbitals.
• Carbon forms complex compounds. To a maximum of 4 supplemental atoms, it may form bonds. This allows it to form a long chain of 70-80 carbon atoms. These atoms are then linked by covalent bonds. The bonded electrons of the carbon nucleus are also bonded to the other atoms in the chain. This results in a series of bonds that are allotropic.
• The valence shell of carbon has four pairs of electrons, which are located at the outermost regions of the shell. Since atoms are so tiny, this is the consequence. These small atoms make it easier to form bonds. A carbon atom is highly electronegative, and it attracts electrons towards itself. This makes it easier to form bonds, especially multiple bonds.

4. Trend in the physical properties

These elements show following trend in their physical properties (Arias & Coppola, 2021).

 

4.1. Atomic and ionic radii

Atomic and ionic radius of group 14 elements increases gradually from carbon to lead while ionic radii of Flerovium is unknown.
Group 14 elements are relatively small compared to the elements of group 13. The difference in their atomic radii is not very significant.

 

Atomic radius group 13 periodic table

 

Figure 1: Atomic radius of Group 14 elements

 

Ionic radius group 13 periodic table

 

Figure 2: Ionic radius of Group 14 elements

 

4.2. Ionization energy

When compared to their counterparts in Group 13, the ionization efficiency of Groups 14 elements is greater. The increased nuclear charge in the group 14 elements is responsible for this. These elements have decreasing radii due to an increase in nuclear charge. The atomic radius grows further away from the nucleus. Similarly ionization energy of group 14 elements decreases from carbon to tin while I.E of lead is greater than tin and I.E of Fl is greater than all the member of its group except carbon.
Ionization energy of group 14 elements in kilo joule per mole

 

First ionization energy group 13 periodic table

 

Figure 3: First Ionization Energy of the Group 14 elements

4.3. Electronegativity

Electronegativity of carbon is greater than decrease all its group members and this value is decrease from carbon to silicon while Electronegativity of Si, Ge and Sn is equal. Electronegativity of Pb is greater than Sn and Electronegativity of Fl is unknown.

 

C     2.5

Si    1.8

Ge   1.8

Sn    1.8

Pb    1.9

4.4. Melting and boiling point

Boiling point of group 14 elements decrease gradually from Carbon to lead. Melting point of this group elements also decrease gradually from Carbon to Germanium while m.p of lead is greater than previous member (Sn) .This value is unknown for Fl.

 

melting and boiling points group 13 periodic table

 

Figure 4: Melting and Boiling Points of the Group 13 elements

 

5. Chemical properties

Several chemical properties of group 14 elements are known. These elements are mostly represented in the 4 covalently complexes. Some important reaction of this group elements are given below.

5.1. Reaction with oxygen

Group 14 elements reacts with oxygen and form corresponding oxide.

 

Reaction of Group 13 elements with Oxygen

Scheme 1: Reaction of Group 14 elements with Oxygen

 

5.2. Reaction with hydrogen

Carbon and silicon reacts with hydrogen and form different compounds.

 

Reaction of Group 13 elements with water

Scheme 2: Reaction of Group 14 elements with water

 

5.3. Reaction with halogens

Carbon in the form of alkene reacts with halogen and form halide. While silicon reacts with halogen and form tetrahalides.

 

Reaction of Group 13 elements with halogens

Scheme 3: Reaction of Group 14 elements with halogens

 

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Conclusion

Known as the Carbon Family, Group 14 Elements are chemical elements belonging to the p block of the periodic table. The group contains the elements silicon, Germanium, Tin and Lead. The name of this group is derived from the Greek word tetra. The elements are named after the first element in the group. The group 14 elements have four valence shell electrons and have two p-orbitals. These elements form cations with a +4 charge.

 

References

1. Asay, M., Jones, C., & Driess, M. (2011). N-Heterocyclic carbene analogues with low-valent group 13 and group 14 elements: syntheses, structures, and reactivities of a new generation of multitalented ligands. Chemical reviews, 111(2), 354-396.
2. Thursz, M. R., Richardson, P., Allison, M., Austin, A., Bowers, M., Day, C. P., … & Forrest, E. H. (2015). Prednisolone or pentoxifylline for alcoholic hepatitis. New England Journal of Medicine, 372(17), 1619-1628.
3. Arias, P., Bellouin, N., Coppola, E., Jones, R., Krinner, G., Marotzke, J., … & Zickfeld, K. (2021). Climate Change 2021: The Physical Science Basis. Contribution of Working Group14 I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change; Technical Summary.