What are Covalent Bonds?

A covalent bond refers to the bonding between atoms when they exchange electrons with each other to form electron pairs. A covalent bond is one of the most basic yet important topics of chemistry as it includes the proper understanding of atoms, electrons, and how they work with each other. A covalent bond definition can be given as a stable equilibrium of the attractive and repulsive forces between atoms to share electrons.

Due to electrons being negatively charged, the stronger atom receives a tiny negative charge as it has a higher proportion of electrons. Similarly, the weaker atom gains a tiny amount of positive charge, balancing off the stronger atom. This is how they balance the bond to combine into new elements.

Covalent bond examples include H2O or water, which is formed with the combination of electrons of hydrogen and oxygen, or CO2 which is formed with the combination of electrons of carbon and oxygen. 

What are the types of Covalent Bonds?

Usually happening between non-metals and depending upon the number of shared electron pairs, covalent bonds can be categorized into three types: Single Covalent Bonds, Double Covalent Bonds, and Triple Covalent Bonds.

1. Single Covalent Bonds: When just one pair of electrons is shared by the cooperating atoms, a single bond is created. It is depicted by a single dash (-). Although weaker than double and triple bonds and with a lower density, this type of covalent bond is the most stable. Single covalent bond examples include HCl or NH3.
2. Double Covalent Bonds: When two pairs of electrons are shared by the cooperating atoms, a double bond is created. The symbol for it is two dashes (=). Although they are less stable, double covalent bonds are substantially more powerful than single ones. Examples of double covalent bonds include CO2, O2, etc.
3. Triple Covalent Bonds: When three pairs of electrons are shared by the two cooperating atoms, a triple bond is created. The least stable covalent bonds are triple covalent bonds, which are denoted by three dashes (≡). N2, C2H2, etc. are examples of triple covalent bonds.

Moreover, depending on each electron's propensity and chemistry, covalent bonds can be categorized into three other types: Polar Covalent Bonds, Non-polar Covalent Bonds and Coordinate Covalent Bonds. 

1. Polar Covalent Bonds: This kind of covalent bond exists when interacting atoms have different electro-negativities, resulting in an unequal sharing of electrons. More electronegative atoms will draw more electrons. Between the atoms, there is an electronegative difference that is larger than 0 but less than 2.0. The common pair of electrons will consequently be nearer to that atom as a result. In easy words, a bond between a negatively charged and a positively charged electron is called a polar covalent bond. For example, oxygen.
2. Non-polar Covalent Bonds: When there is an equal sharing of electrons among the atoms, this kind of covalent bond is created. There is no difference in the electronegativity of the two atoms. Wherever the combining atoms have comparable electron affinities, it happens. Examples of non-polar covalent bonds include nitrogen and hydrogen gasses.
3. Coordinate Covalent Bonds: A coordinate covalent bond is a type of two-electron covalent connection wherein the two electrons originate from the same atom. This type of interaction occurs during the bonding of metal ions to ligands. Examples of coordinate covalent bonds include the formation of Hydronium or Ammonium ions.

So, now we know that a covalent bond is a balance of sharing electrons between two atoms. It is important to learn about them to realize the combination of molecular bonding in forming elements. Since most interactions between carbon molecules include covalent bonds, they are particularly significant. By sharing electrons through covalent bonds, molecules can form extended chains of compounds to add complexity to life. Covalent bonds hold many of the molecules in our environment together. Examples of molecules with covalent bonds include sugar molecules, diamonds, and plastic as well as airborne gasses like oxygen, carbon dioxide, nitrogen, etc. There are multiple virtual lab equipment online that helps in calculating and researching topics, and would help you all to know more about the subject.