A chemical bond is the phenomenon of atoms being held together in molecules or crystals. All chemical bonds are due to electrons interacting simultaneously with the atoms in question. These electrons are normally part of an atom's atomic orbital (AO), but in a bond, they thus form a molecular orbital (MO). These elecron-nucleus interactions are caused by the fundamental force of electromagnetism. Atoms will form a bond if their orbitals become lower in energy when they interact with each other. Properties For alternative meanings see atom (disambiguation). ... A molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... Quartz crystal A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ... Properties The electron is a subatomic particle. ... Electron atomic and molecular orbitals In quantum mechanics, the states of an atom, i. ... Electron atomic and molecular orbitals In quantum chemistry, the molecular electronic states, i. ... The nucleus (atomic nucleus) is the center of an atom. ... A fundamental interaction is a mechanism by which particles interact with each other, and which cannot be explained by another more fundamental interaction. ... Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ...

There are 5 different types of chemical bonds that we use to categorize atomic interactions. These classifications are defined by electron cloud shape and by energy levels. Actual bonds have properties that aren't so discretely categorized, so a given bond could be defined by more than one of these terms. Electron atomic and molecular orbitals In atomic physics, the electron configuration is the arrangement of electrons in an atom, molecule or other body. ... In physics and quantum chemistry, an energy level is a quantized energy of a bound quantum mechanical state. ...

The five types of chemical bonds:

• ionic bond
• covalent bond
• coordinate covalent bond
• metallic bond
• hydrogen bond

The electrons in the MO of a bond are said to be either “localized” on certain atom(s) or “delocalized” between two or more atoms. The type of bond between two atoms is defined by how much the electron density is localized or delocalized among the atoms of the substance. An ionic bond can be formed after two or more atoms give up (or gain) electrons, so as to become ions. ... Covalently bonded hydrogen and carbon in a molecule of methane. ... A coordinate covalent bond (also known as dative covalent bond) is a special type of covalent bond in which the shared electrons come from one of the atoms only. ... Metallic bonding is bonding within metals. ... http://www. ... Electron density is the measure of the probability of an electron being present at a specific location. ...

Many simple compounds involve covalent bonds. These molecules have structures that can be predicted using valence bond theory, and the properties of atoms involved can be understood using concepts such as oxidation number. Other compounds that involve ionic structures can be understood using theories from classical physics. However, more complicated compounds such as metal complexes cannot be described by valence bond theory, and we need quantum chemistry (based on quantum mechanics) to help us understand these molecules. Covalently bonded hydrogen and carbon in a molecule of methane. ... The valence bond theory considers the overlap of the atomic orbitals of the participation atoms to form a chemical bond. ... The oxidation state or oxidation number is defined as the sum of negative and positive charges in an atom, which indirectly indicates the number of electrons it has accepted or donated. ... Classical physics is physics based on principles developed before the rise of quantum theory, including the special theory of relativity. ... A complex in chemistry and biochemistry is a reversible association of molecules, atoms, or ions through weak non-covalent chemical bonds. ... Quantum chemistry is a branch of theoretical chemistry, which applies quantum mechanics to problems in chemistry. ... Fig. ...

In the case of ionic bonding, electrons are mainly localized on the individual atoms, and electrons do not travel between the atoms very much. Each atom is assigned an overall electric charge to help us conceptualize the MO's distribution. The forces between atoms (or ions) are largely characterized by isotropic continuum electrostatic potentials. Isotropic means independent of direction. Isotropic radiation has the same intensity regardless of the direction of measurement, and an isotropic field exerts the same action regardless of how the test particle is oriented. ...

By contrast, in covalent bonding, the electron density within bonds is not assigned to individual atoms, but is instead delocalized in the MOs between atoms. The widely-accepted theory of the linear combination of atomic orbitals (LCAO) helps describe the MOs' structures and energies based on the AOs of the atoms they came from. Unlike pure ionic bonds, covalent bonds may have directed anisotropic properties. In molecular physics, the linear combination of atomic orbitals molecular orbital method (usually called the LCAO MO method) is a technique for calculating molecular orbitals in quantum chemistry. ... This article is being considered for deletion in accordance with Wikipedias deletion policy. ...

Atoms can also form bonds that are intermediates between ionic and covalent. This is because these definitions are based on the extent of electron delocalization. Electrons can be partially delocalized between atoms, but spend more time around one atom than another. This type of bond is often called “polar covalent”.

These chemical bonds are intramolecular forces that keep atoms held together in molecules. There are also intermolecular forces that cause molecules to be attracted or repulsed by each other. These forces include ionic interactions, hydrogen bonds, dipole-dipole interactions, and induced dipole interactions. Intermolecular forces are electromagnetic forces which act between molecules or between widely separated regions of a macromolecule. ... In chemistry, a hydrogen bond is a type of attractive intermolecular force that exists between two partial electric charges of opposite polarity. ... Intermolecular forces are electromagnetic forces which act between molecules or between widely separated regions of a macromolecule. ... Intermolecular forces are electromagnetic forces which act between molecules or between widely separated regions of a macromolecule. ...

Linus Pauling's book The Nature of the Chemical Bond is perhaps the most influential book on chemistry ever published. Linus Carl Pauling (February 28, 1901 – August 19, 1994) was an American physical chemist, widely regarded as the premier chemist of the twentieth century. ...

See also

• atomic orbital
• binding energy
• bond dissociation energy
• double bond
• periodic table
• Van Arkel-Ketelaar triangle

Electron atomic and molecular orbitals In quantum mechanics, the states of an atom, i. ... Binding energy is the energy required to disassemble a whole into separate parts. ... In chemistry, bond dissociation is a process in which a specific bond is cleaved to give two new species. ... Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ... The periodic table of the chemical elements, also called the Mendeleev periodic table, is a tabular display of the known chemical elements. ... Bond triangles or Van Arkel-Ketelaar triangles are triangles used to show different compounds in varying degrees of ionic, metallic and covalent bonding. ...

References

• W. Locke (1997). Introduction to Molecular Orbital Theory. Retrieved May 18, 2005.
• Carl R. Nave (2005). HyperPhysics. Retrieved May 18, 2005.