Introduction to Covalent Bonding in Carbon Atoms

Introduction and Explanation:

Compounds:  

A compound is a pure substance made up of two or more kinds of elements that are chemically combined. When they combine, the atoms of one element make connections with the atoms of another element in very specific ways. 

Compounds are of two types they are:

1. Organic compounds
2. Inorganic compounds

Organic Compounds:

Organic compounds are the chemical compounds where we mostly have carbon and in addition with other elements like hydrogen, oxygen, and nitrogen which are covalently bonded in atoms. Carbides, carbonates, and cyanides form the only carbon-containing compounds not known as organic.

Examples: Wax, polyester, silk, paper, polyethylene, soaps, detergents, and many medicines are organic; all are useful organic compounds. 

Inorganic Compounds:

Inorganic compounds are chemical compounds where we take fewer carbon atoms. They do not possess hydrogen or oxygen and their derivatives.

Examples: Table salt, hydrochloric acid, carbon dioxide, quartz, diamond etc., are useful examples of inorganic compounds.

The word ‘organic’ means pertaining to life. When comparatively little chemistry was known, people thought that substances like sugar, starch, protein, and acetic acid could be obtained only.

As against these compounds, substances like common salt, blue vitriol, nitrate etc., could be produced from minerals and non-living things are called inorganic compounds.

As we know, the amount of carbon that is present in the earth’s crust and the atmosphere are quite mixed. The earth’s crust has only 0.02% carbon and the atmosphere has 0.03% carbon dioxide. All living structures are carbon-based.

Introduction of Carbon: 

1. Carbon is one of the most significant non-metallic elements. 
2. All compounds, such as proteins, carbohydrates, and fats, contain carbon, and all plant and animal cells consist of carbon compounds. 
3. The atomic number of carbon is six, and the mass number is 12. 
4. Carbon contains a total of 6 electrons, out of which it contains 4 electrons in its outermost shell; therefore, the valency of carbon is 4. 
5. It is the third most important element after hydrogen and oxygen for the existence of life on Earth. 

Some of the organic and inorganic compounds of carbon: 

Bond: The attractive force between the electrons and the protons in an element depends on the structure and the number of electrons and protons. Based on it, some elements are unstable as the nucleus cannot hold the electrons around them. They try to move to the other elements forming a compound. This is called bonding. These bonds are chemical bonds. 

Ionic Bond: Ionic bond is a type of bond in which the transfer of electrons takes place from one atom or molecule. An ionic bond is seen between metal and non-metal. In an ionic bond, one atom loses electrons and it transfers it to the other atom which gains the electrons.

The bond that forms as a result of the strong electrostatic force of attraction between a positively and negatively charged species is called an electrovalent or ionic bond.

• They have high melting and boiling points.
• The ionic compounds that dissolve in water are good conductors of electricity.
• The charges of the ions and the forces that hold them together in the compound are responsible for the properties of ionic compounds. 

Covalent Bond in Carbon:

Covalent bond: When the sharing of electrons takes place in a compound is called a covalent bond.

Mostly for all the organic compounds, a covalent bond is formed between the atoms to hold the force of attraction.

The carbon atomic number is 6 and the electronic configuration of carbon is 2, 4. If carbon has to attain noble gas configuration, it requires 4 more electrons to get the carbon stable.

• Carbon is very difficult to either lose or gain electrons as it would be difficult to hold extra electrons and would require a large amount of energy to remove four electrons.

It could gain four electrons forming C^4– anion. But it would be difficult for the nucleus with six protons to hold on to ten electrons, that is, four extra electrons.

It could lose four electrons forming C⁴⁺ cation. But it would require a large amount of energy to remove four electrons leaving behind a carbon cation with six protons in its nucleus holding on to just two electrons.

• Carbon attains a stable electronic configuration by sharing valence electrons with another element. The mutual sharing of electrons between the atoms to attain a stable configuration is called covalent bonding.
• A covalent bond is formed between two nonmetals, one should be paired and another one should be unpaired.
• The sharing of valence electrons can be seen in atoms of other elements like hydrogen, oxygen, nitrogen, and chlorine.

Depending on the Number of Electrons Pairs Shared, a Covalent Bond Is of Three Types:

1. Single covalent bond: A single covalent bond is formed because of the sharing of two electrons which means one pair.

Example: Hydrogen, chlorine, methane.

2. Double covalent bond: Double bond is formed by the sharing of four electrons that means two pairs of electrons.

Example: O₂ molecule, CO₂ molecule.

3. Triple covalent bond: Triple covalent bond is formed because of the sharing of six electrons which means three pairs of electrons.

Example: N₂, Ethyne.

From the data given in Table 4.1 on the boiling and melting points of the carbon compounds, we find that these compounds have low melting and boiling points as compared to ionic compounds.

Since these compounds are largely non-conductors of electricity, we can conclude that the bonding in these compounds does not give rise to any ions.

What would be the distribution of electrons in various shells of carbon?

Carbon

The atomic number of carbon is 6. The electronic configuration of carbon is

C(Z = 6) = 1s² 2s²2p²

The distribution of electrons in the carbon atom is as follows:

• In the first orbit or K-shell = 2 electrons
• In the second orbit or L-shell = 4 electrons

Or, we can write the distribution of electrons in a carbon atom as 2, 4.

Electrons Dot Structure:

The electron dot structure provides a picture of bonding in molecules in terms of the shared pairs of electrons and octet rules.

Formation of Hydrogen Molecule:

The atomic number of hydrogen=1

Valency=1

Valence electrons=1

A hydrogen atom has one unpaired electron and it needs one more electron to form the hydrogen molecule

The hydrogen atom combines and shares its electrons to form a covalent bond with another unpaired electron of another atom.

Formation of CH₄ Molecule:

The atomic number of carbons is 6 and its electronic configuration is 2, 4

The atomic number of Hydrogen is 1 and its electronic configuration is 1

Valency of carbon=4

Valence electrons=4 and valence electrons of Hydrogen=1

As in carbon, there are only 4 valence electrons and it needs 4 more electrons to get stabilized.

Hydrogen shares one electron with carbon to form one covalent bond in the same 4 electrons of 4 hydrogen will be sharing its electron to one carbon atom to form methane molecule.

Formation of CO₂ Molecule:

The atomic number of oxygen is 8 and its electronic configuration is 2, 6

The atomic number of carbon is 6 and its electronic configuration is 2, 4

Valence electrons of carbon=4

Valence electrons of oxygen=6

    Summary

• Organic compounds are the chemical compounds where we mostly have carbon and in addition with other elements like hydrogen, oxygen, and nitrogen which are covalently bonded in atoms.
• Inorganic compounds are chemical compounds where we take fewer carbon atoms. They do not possess hydrogen or oxygen and their derivatives.
• All compounds, such as proteins, carbohydrates, and fats, contain carbon, and all plant and animal cells consist of carbon compounds. 
• The carbon atomic number is 6 and the electronic configuration of carbon is 2, 4. If the carbon has to attain noble gas configuration, it requires 4 more electrons to get the carbon stable.
• Carbon is very difficult to either lose or gain electrons as it would be difficult to hold extra electrons and would require a large amount of energy to remove four electrons.
• Single covalent bond is formed because of the sharing of two electrons that one pair.
• Double bond is formed by the sharing of four electrons which means two pairs of electrons.
• Triple covalent bond is formed because of the sharing of six electrons which means three pairs of electrons.