Carbon and carbon compounds


Carbon was discovered by French scientist Antoine Lavoisier. Carbon is the toughest structure, usually present in hard materials such as diamonds and graphite. In the periodic table, it’s the most versatile element. Carbon is present in various forms, they are almost present everywhere within and outside our body. We can find them in the materials that we use in our day to day life; pencils, bags, and some electric equipment. Our atmosphere has carbon in the form of C02. The earth’s crust has a minimal amount of (0.02%) carbon in the form of carbonates, hydrogen, coal and petroleum products, One of the important features of carbon is that it exists in multiple Physical Forms.



1. Carbon- facts and figures

2. The covalent bond in the carbon

3. Melting and boiling points of common carbon compounds

4. Covalent bonding in Carbon and carbon compounds

5. Covalent bonding in Carbon and carbon compounds


    5.1 Covalent Bonding of Hydrogen Molecule

    5.2 Covalent Bonding of Carbon Compounds

6. Examples of covalent bonding

Carbon- facts and figures

  1. Carbon has an atomic number 6 and its atomic weight is 12

  2. Its allotropes are graphite, diamond, amorphous carbon in the form of coal and soot atomic Carbon, graphene, etc.

  3. It is indicated by the  symbol “C”( Capital)

  4.  Carbon has 4 electrons in its valence shell

  5. The density of carbon is 2.2670 grams per cubic centimetre

  6. Carbon stays in its original solid-state in the  Room Temperature

  7. Melting Point is very high .i,e  6,422 degrees Fahrenheit or 3,550   degree C

  8. Boiling Point: 6,872 F (3,800 C) (sublimation)

  9. Tere are a total of 15  isotopes  and the most common isotopes are  carbon-12 (6 protons, 6 neutrons and 6 electrons) and carbon-13 (6 protons, 7 neutrons and 6 electrons)\


The covalent bond in the carbon

We learn that most ionic compounds have higher melting and boiling points and they are conductors of electricity in their liquid form (molten state). Some of the properties of carbon compounds are explained in the table below.


Melting and boiling points of common carbon compounds





Melting  point


Boiling point

Acetic acid (CH3COOH)




Chloroform (CHCl3)




Ethanol (CH3CH2OH)




Methane (CH4)





Covalent bonding in Carbon and carbon compounds

  1. A covalent bond is a chemical bond during which, pairs of electrons are shared between the two atoms. The force at which the attraction or repulsion takes place between the two atoms while sharing their electron pair is known as covalent Bonding.

  2. Carbon has a total of four electrons in its outer shell. It has the ability to form an innumerable number of molecules and bonds by mutually sharing the electrons and that’s the reason carbon has many variants (allotropes).


Examples of covalent bonding

1. Covalent Bonding of Hydrogen Molecule

  1. Hydrogen will not be able to exist in its original form so, it must get bound with another atom forming H2.

  2. In this case, a single atom of hydrogen has one electron, i.e. it`s an atomic number is 1 because it has a single electron in it`s first and the only orbit. As already mentioned, it should be in H2 form in order to be stable, hence, it remains unstable until it attains one more electron to form H2. Here the valency of hydrogen is 1.

  3. Since the valency of an atom depends on the ability to share it`s electrons, so the hydrogen atom shares it`s a single atom with another hydrogen atom to form H2 as a complete and stable structure.

  4. Ultimately, both the hydrogen atoms have two shared electrons in its outer shell which is a stable molecule of H2 and such a bond is formed by sharing the electrons is nothing but a covalent bond.


2. Covalent Bonding of Carbon Compounds

  • These are formed when there is a carbon-carbon bond and as it can happen in many carbon compounds. The ability to form a covalent bond in a carbon compound is because it has a strong capacity of bonding than any other compounds hence, the diamond, coal, and metals are very hard and strong.

  • In addition, carbon tends to create a very strong force of attraction with it`s smaller atomic size. Another interesting fact is, carbon is capable of sharing or losing, and also gaining electrons which is necessary for the reactivity of elements. So, carbon has 4 electrons in its outermost shell. But, one of the following circumstances must be present in order to form a covalent bond.

  1. Carbon can lose all the 4 electrons to become a complete cation i.e. C4+. But, in order to lose all 4, it requires a lot of energy, and the final atom mill is highly unstable with 6 neutrons holding only two electrons in one shell which creates an imbalance.

  2. The next option is that a carbon atom can completely gain 4 electrons from another atom, but, the resulting carbon atom won’t be stable.  If it happens so, then 10 electrons must be held by six neutrons in the nucleus.

  3. Since both the above equations are impossible, carbon forms a unique bonding strategy by sharing it`s valence electrons with other carbon atoms or even atoms of other elements.

  4. The shared atoms of the last shell belong to both the atoms, hence forming a bond between these atoms can lead to a completely balanced outer shell with 8 atoms. At the same time, both of them attain a noble gas configuration. This sharing of atoms, instead of gaining or losing is called covalent bonding.


Important carbon compounds with their covalent bonding

Methane: Methane has a chemical formula of CH4, which means a single atom of carbon combines with 4 atoms of hydrogen to configure one molecule of methane. All 4 hydrogen atoms have a single electron in their outermost shell but carbon has 4 electrons. So carbon will share each of the 4 electrons with one atom of carbon this makes carbon a complete octet with all 4 hydrogen atoms having a complete duplet. In methane, Carbon has 4 un-shared electrons in its valence shell which looks imbalanced. In order to balance the octet, carbon requires 4 additional electrons and these 4 electrons are donated by 4 hydrogen atoms, forming 4 covalent bonds on all 4 sides. These covalent bonds, in this case, are known as nonpolar covalent bonds as the end result of such an equal sharing of electrons between carbon and hydrogen is that there is no charge separation or dipole movement in the final structure.


Carbon dioxide

If you take for example of  CO2 molecule, it is formed by combining 2 atoms of oxygen with one atom of carbon. Since carbon has 4 free-electrons in its outer shell,  and the oxygen with 6 atoms in the last shell, carbon shares 2  of the atoms with each atom of the oxygen. This phenomenon will complete their octet giving us one stable co2 molecule.





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