por What are interatomic bonds?
The links interatomic They are the chemical bonds that form between atoms to produce molecules. Although today scientists generally agree that electrons do not revolve around the nucleus, throughout history it was thought that each electron orbited the nucleus of an atom in a separate shell.
Today, scientists have concluded that electrons hover in specific areas of the atom and do not form orbits, yet the valence shell is still used to describe the availability of electrons.
Linus Pauling (1901-1994) contributed to the modern understanding of chemical bonding by writing The nature of the chemical bondwhere he collected ideas from Sir Isaac Newton, Étienne François Geoffroy, Edward Frankland and in particular Gilbert N. Lewis.
In it, he linked the physics of quantum mechanics with the chemical nature of electronic interactions that occur when chemical bonds are made.
Pauling’s work concentrated on establishing that true ionic bonds and covalent bonds lie at the extremes of a bonding spectrum, and that most chemical bonds fall between those extremes.
Pauling further developed a bond-type sliding scale governed by the electronegativity of the atoms participating in the bond.
The immense Pauling’s contributions to the modern understanding of chemical bonding led to his being awarded the 1954 Nobel Prize for «investigation into the nature of chemical bonding and its application to the elucidation of the structure of complex substances.»
Living things are made up of atoms, but in most cases, those atoms don’t just float around individually. Instead, they are typically interacting with other atoms (or groups of atoms).
For example, atoms can be connected by strong bonds and organized into molecules or crystals. Or they can form temporary, weak bonds with other atoms that collide with them.
Both strong bonds, which hold molecules together, and weak bonds, which create temporary connections, are essential to the chemistry of our bodies and to the existence of life itself.
Atoms tend to arrange themselves in the most stable patterns possible, which means that they have a tendency to complete or fill their outermost electron shells.
They join with other atoms to do just that. The force that holds atoms together in collections known as molecules is known as a chemical bond.
Types of interatomic chemical bonds
metal bond
The metallic bond is the force that holds the atoms together in a pure metallic substance. Such a solid consists of closely packed atoms.
In most cases, the outermost electron shell of each of the metal atoms overlaps with a large number of neighboring atoms. As a consequence, valence electrons continually move from one atom to another and are not associated with any specific pair of atoms.
Metals have several qualities that are unique, such as the ability to conduct electricity, low ionization energy, and low electronegativity (so they donate electrons easily, ie, they are cations).
Their physical properties include a shiny appearance, and they are malleable and ductile. Metals have a crystalline structure.
In the 1900s, Paul Drüde came up with the theory of the sea of electrons by modeling metals as a mixture of atomic nuclei (atomic nuclei = positive nuclei + inner electron shell) and valence electrons.
In this model, the valence electrons are free, delocalized, mobile, and not associated with any particular atom.
ionic bond
Ionic bonds are electrostatic in nature. They are produced when an element with a positive charge binds to one with a negative charge by coulombic interactions.
Elements with low ionization energies tend to lose electrons easily, while elements with high electron affinity tend to gain them by producing cations and anions respectively, which form ionic bonds.
Compounds that show ionic bonding form ionic crystals in which ions with positive and negative charges oscillate close to each other, but there is not always a direct 1-1 correlation between positive and negative ions.
Ionic bonds can typically be broken through hydrogenation, or the addition of water to a compound.
Substances held together by ionic bonds (such as sodium chloride) can commonly separate into true charged ions when acted upon by an external force, such as when dissolved in water.
Also, in solid form, individual atoms are not attracted to an individual neighbor, but instead form giant lattices that are attracted to each other by electrostatic interactions between each atom’s nucleus and neighboring valence electrons.
The attractive force between neighboring atoms gives ionic solids an extremely ordered structure known as an ionic lattice, where oppositely charged particles align with each other to create a rigid, tightly bound structure.
Covalent bond
Covalent bonding occurs when electron pairs are shared by atoms. Atoms will covalently bond with other atoms to gain more stability, which is obtained by forming a complete electron shell.
By sharing their outermost (valence) electrons, atoms can fill their outer shell with electrons and gain stability.
Although atoms are said to share electrons when they form covalent bonds, they do not usually share electrons equally. Only when two atoms of the same element form a covalent bond are the shared electrons actually shared equally between the atoms.
When atoms of different elements share electrons through covalent bonding, the electron will be drawn more toward the atom with the higher electronegativity, resulting in a polar covalent bond.
When compared to ionic compounds, covalent compounds usually have a lower boiling and melting point and are less likely to dissolve in water.
Covalent compounds can be in a gas, liquid, or solid state, and they do not conduct electricity or heat well.
Hydrogen bonds
Hydrogen bonds, or hydrogen bonds, are weak interactions between a hydrogen atom attached to an electronegative element with another electronegative element.
In a polar covalent bond that contains hydrogen (for example, an OH bond in a water molecule), the hydrogen will have a slight positive charge because the bonding electrons are pulled more strongly toward the other element.
Because of this slight positive charge, the hydrogen will be attracted to any neighboring negative charges.
Van der Waals Links
They are relatively weak electrical forces that attract neutral molecules to each other in gases, in liquefied and solidified gases, and in almost all organic liquids and solids.
The forces are named after the Dutch physicist Johannes Diderik van der Waals, who in 1873 first postulated these intermolecular forces in developing a theory to explain the properties of real gases.
Van der Waals forces is a general term used to define the attraction of intermolecular forces (between molecules).
There are two kinds of van der Waals forces: London dispersion forces, which are weak, and stronger dipole-dipole forces.
References
Covalent Bonds. Retrieved from chem.libretexts.org
Metallic Bonding. Retrieved from chem.libretexts.org
Metallic bond. Recovered from britannica.com.