Chemical bonds

Force interaction, which energetically stabilizes the combined atoms and contributes to the formation of the molecule
The molecule has a lower energy than the original single atoms had before the merger

Binding energy - the energy which is released by bond formation - the greater the value of this energy, the atoms are tightly bonded to each other

Dissociation energy of bond - the energy which is necessary to deliver for split of bond

The length of bond - is the distance between the nuclei of atoms - is determined by spectral methods

The bond strength - increases with increasing binding regulations - multiplicity

Covalent bond
The electrons are shared so that each fill part of the valence electron shell
In organic compounds and inorganic molecules with a crystal lattice consisting of the same atoms, for example: diamond

σ bond is at the junction of cores and π bond is outside of junction of cores
At room temperature compounds are liquid or gaseous

Coordination - covalent bond
= Donor-acceptor bond
Donor - Provides free electron pair
Characteristics do not differ from covalent bonds
Especially in complex compounds

Nonpolar bond
Difference of electronegativity is less than 0.4
Molecules composed of the same atoms, carbon dioxide, methane, etc. have this bond

Polar bond
Difference of electronegativity is 0.4 < X <1.67
Shared electrons are attracted to one of the atom more
It occurs in water, methanol, glycerol, inorganic compounds, formic acid, acetic acid

Ionic bond
Difference of  electronegativity is greater than 1.67
One atom attracts one or more electrons from another atom - with electrons reaches a stable electron configuration and becomes an anion = negative ion and second atom becomes cation = positive ion
Ionic compounds are dissolved in water
The strongest ionic bond occurs with metal salts

Metallic bond
Valence electrons of atoms are freely shared --> ions are surrounded by "electron gas"
The presence of free electrons results in a high thermal and electrical conductivity, a regular crystal lattice

Weak bonding interactions
Hydrogen bonds
H has the ability of interact with two strongly electronegative elements
Occurs between hydrogen atoms and O, N, F

Van der Waals forces
Irregular placement and movement of electrons
The most commonly occur among nonpolar molecules