Chemical bond - Explanation and definition of chemical bonds
What is Chemical bond
Chemical bond is the physical-chemical phenomenon whereby atoms, ions and the same or different molecules join with each other to result in stable compounds or other molecules with different characteristics and properties of the initial elements. Chemical bonds are directly responsible for both the chemical and physical properties of all substances in the universe.
We may liken the chemical bond as the universal "glue" that holds the atoms and molecules that shape all matter around us like trees, water, earth, moon, sun ... The whole universe exists thanks the chemical bonds without these would be scattered all roaming atoms in space. Furthermore thanks to chemical bonds the 118 discovered elements currently located in the periodic table are joined with other resulting in billions of different chemical compounds each.
Chemical bonds are the cornerstones of the chemical, its design dates back to the ancient Greek philosophers such as Leucippus or Democritus which defended the atomic theory by which exposed the whole material nature was made up of small and indivisible particles called atoms, which they are connected to one another by hooks available to the atoms themselves or through a mysterious glue.
It was not until 1718 when the physicist and mathematician Sir Isaac Newton was the first to introduce the concept of force as a means of bonding that occurred between atoms, so atoms attract each other by means of attractive forces which lose intensity as the atoms are distanced from each other.
Subsequently many scientists like William Higgins, Edward Frankland, Ludwig Boltzmann, Gilbert Lewis or Linus Pauling have contributed to the progress science and define different models to meet one of the basic pillars of science, why and how to join the atoms?.
Basically we can say that there are 2 types of chemical bonds in nature:
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Intramolecular bonds
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Intermolecular bonds
Intramolecular bonds refer to the forces that hold the atoms within a molecule, while intermolecular bonds refer to the forces holding different molecules or ions within a chemical compound.
Intramolecular bonds
Intramolecular bonds are responsible for holding together the different atoms that form a molecule and determine the chemical properties of substances, are divided basically in 3 other types of links:
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Covalent bond
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Ionic bond
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Metallic bond
The covalent bond refers to the force that holds nonmetal atoms by share electrons of the last layer, said sharing of electrons is what causes the atoms do not separate, still connected to one another to shape the molecules.
Ionic bonding refers to the force that holds metal atoms with no metal atoms, metal atoms contribute electrons to yield non-metal atoms giving rise to pairs of positive and negative ions that are attracted to each other by the intense electrostatic attraction forces that develop between two oppositely charged.
While the covalent bond force that holds the atoms occurs by a sharing of electrons in the ionic bonding force that holds the atoms it occurs by an exchange of electrons.
Finally the metallic bonding occurs between metal atoms which are packaged with other electron releasing its last layer, resulting in positively charged dimensional structures surrounded by a cloud of negatively charged electrons developed intense electrostatic attraction forces between the network three-dimensional and the electron cloud.
Intermolecular bonds
Intermolecular bonds are responsible for maintaining the different molecules of a compound are joined and determine the physical properties of the substance as the color, density or the melting point.
Mainly we can divide the intermolecular forces into 4 groups or families:
Dipole - dipole
Dipole - dipole induced
Instantaneous dipole - dipole induced
Hydrogen bonds
When a molecule it form of two different atoms, most of the electrons are attracted by the more electronegative atom resulting in areas within the molecule itself with higher electron density giving it a negative charge and other forms in the absence of electrons where they provides some positive charge. When the reorganization of electrons within a molecule itself happens we say that has given rise to a dipole.
Dipole-dipole bond occurs when two molecules are joined by electrostatic attraction caused between the negative with their positive areas.
Dipole - dipole induced occurs when one of the molecules with high electronegativity induces another molecule rearranging the location of their electrons and leading to a dipole which binds to the above by electrostatic attraction forces arising from opposite charges.
Instantaneous dipole - dipole induced occurs when a molecule instantly reorganizes the location of inducing electrons to other molecules to adjacent dipoles generating creating new attraction forces.
These first three types of bonds are also known as Van der Waals force.
Finally the hydrogen bonds is a special type of dipole-dipole intervening the hydrogen atom located between two electronegative atoms, hydrogen bonds contribute to the stability of many organic compounds such as proteins or DNA.
With this we can appreciate the key role occupied by electrons in the development of chemical bonds and electrostatic forces.
Now that you know what are the chemical bond, the answer to the question why atoms come together? we can answer as follows; like people, the atoms bond with other thanks to attractive forces (electrostatic forces of opposite sign) and to achieve a greater degree of stability.
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