Carbon is one of those unique elements because of its tetravalent nature. For some elements, it is quite easy to predict their charge from their valence electrons. The same applies to carbon but in some instances, it has a negative charge.
Carbon is both highly electronegative and electropositive. Because of this, it rather maintains its tetravalency instead of gaining or losing electrons to form ions. It would rather share electrons in covalent bonding.
However, it can also form ions in different oxidation states and carry a charge.
What then is the charge of carbon? This article covers the uniqueness of carbon, its charge, and why it can form different ions of different charges.
Properties of carbon
- Carbon is a nonmetal in group 14 (IVA) and period 2
- It has an atomic number of 6 and a mass number of 12
- Carbon is a tetravalent atom with 2, 4 electrons in its shells
- Carbon can make ions with oxidation states that range from -4 to +4
- Carbon is the 15th most abundant element on the Earth’s crust and the 4th most abundant in the universe by mass
- It exists in allotropes such as amorphous carbon, diamond, graphite, and fullerenes. Each of the allotropes of carbon has its unique characteristics
- Amorphous carbon has no crystalline structure while the other forms occur in crystalline structures. Graphite carbon is opaque or black with a density of 2.267 g/cm3. Diamond carbon is transparent with a density of 3.515 g/cm3. Amorphous carbon has a density of 1.8 to 2.1 g/cm3
- Furthermore, graphite is soft while diamond is hard
- Also, graphite is a good electrical conductor. Diamond, on the other hand, has low conductivity
- All allotropes of carbon are solid at STP with a boiling point and melting point of 8,721°F(4,827°C) and 6,420°F (3,550°C) respectively
- Carbon is sourced from a wide range of materials that range from inorganic to organic. Inorganic sources of carbon include carbon dioxide, limestone, and dolomites. Organic sources include coal, oil, and methane clathrates
What is the charge of carbon?
The predominant charges on carbon are -4, +2, and +4. However, it has a great tendency to exhibit charges that range from -4 to +4. This is because a carbon atom has four electrons in its valence shell.
Carbon can either gain four more electrons to complete its orbit or lose the four electrons it has in its valence shell. Therefore, the charge depends on whether it gains or loses electrons.
However, carbon with a negative charge, carbanion, is not a stable form of carbon. Also, carbon with a positive charge, carbocation, is not stable either.
It is a tetravalent atom and must always satisfy tetravalency. To always be in a stable form, carbon must share electrons with other atoms.
Why does carbon form negative charges?
Carbon gets a negative charge when it has three bonds and a lone pair of electrons. This ion has five valence electrons and a formal charge of -1.
Why does carbon form positive charges?
Carbocation, carbon as a positive ion, forms when the carbon atom has three bonds and no lone pair of electrons. This ion has three valence electrons and a formal charge of +1.
What is the nuclear charge of carbon?
The nuclear charge of carbon is 6. The nuclear charge of an atom is the total charge on the nucleus of that atom. It is also the same as the atomic number of that element.
FAQs
What is the charge of carbon in CH4?
The charge of carbon in CH4 is -4. If you substitute +1 as the charge of hydrogen in a compound with an overall charge of 0, the mathematical expression will be, C + 4(1) = 0. This gives C a -4 charge.
What is the charge of carbon in carbon dioxide?
The charge of carbon in carbon dioxide, CO2, is +4. In CO2, the charge of each oxygen atom is -2.
C + 2(-2) = 0
C – 4 = 0
+4 = C
What is the charge of carbon in carbon monoxide?
In carbon monoxide, CO, the charge of C is +2, and the charge of O is -2.
Conclusion
Carbon can form a wide range of ions with different charges. But the most common oxidation states are -4, +4, and +2.
Carbon’s tetravalency makes it prioritize retaining its four valence electrons rather than forming ions. The charge will depend on whether it gains or losses electrons.
Carbon has two known oxides, CO2 and CO. They share some similarities but are very different. Learn about the differences with this comparison of CO2 vs CO.
Thanks for reading.