Bond

Chemical bond

Definition :-  Any rearrangement of electrons in two atoms that generates a force, causing the atoms to be bound to each other, forming a molecule.

Example :- covalent bond , ionic bond , hydrogen bond etc.

Definition :-  A chemical bond is an attraction between atoms that allows the formation of chemical substances that contain two or more atoms. The bond is caused by the electrostatic force of attraction between opposite charges, either between electrons and nuclei, or as the result of a dipole attraction. The strength of chemical bonds varies considerably; there are "strong bonds" such as covalent or ionic bonds and "weak bonds" such as dipole–dipole interactions, the London dispersion force and hydrogen bonding.

Types of chemical bond :-

                                       i.            Electrostatic bond, Electrovalent bond, Ionic bond .

                                    ii.            Covalent bond.

                                 iii.            Coordinate covalent bond , Dative bond .

                                  iv.            Metallic bond.

                                     v.            Cross-link, Cross-linkage .

                                  vi.            Peptide bond, Peptide linkage .

                               vii.            Dipole bond, Double bond.

                            viii.            Hydrogen bond .

Ionic bond

Definition :-  The electrostatic attraction between positive (+ive) ions produced by electron transfer is called ionic bond.

                    Example :- NaCl , KCl , MgCl₂ , AlCl₃  etc .

Characteristics of ionic bond

1.   Solid at room temperature. (15 ^oc – 25 ^oc ) .

2.   High melting point .

3.   Hard and brittle .

4.   Soluble in water and polar solvent .

5.   Ionic reaction is very fast.

6.   Conductors of electricity.

Covalent bond

Definition :- The attraction force between atoms created by sharing of an electron pair is called covalent bond.

Example :- H₂ , Cl₂ , H₂O , NH₃ , CH₄ , O₂ etc.

Characteristics of covalent bond

                                                i.            Gases , liquid or solid (soft) at room temperature .

                                             ii.            Low melting point .

                                          iii.            Neither hard or brittle .

                                           iv.            Soluble in organic solvents.

                                              v.            Nonconductors of electricity .

                                           vi.            Exhibit isomerism .

Co-ordinate covalent bond

Definition :- A covalent bond in which both electrons of the shared pair comes from one of the atoms or ions is called coordinate covalent bond.

     Example :- NH₄⁺ , H₃O⁺ , SO₂ , AlCl₃ , etc.

Characteristics of co-ordinate covalent bond

                                                                              I.            They don’t ionized in water .

                                                                           II.            They are very sparingly soluble in water .

                                                                        III.            Don’t conduct electricity .

    

Metallic bond

Definition :- Peculiar types of bonding which holds the atoms together in metal crystal is called metallic bond.

Characteristics of metallic bond

1.   Reflectivity .

2.   Electric conductivity .

3.   Heat conductivity .

4.   Electron emission .

 

Cross-link, Cross-linkage

Definition :-  A side bond that links two adjacent chains of atoms in a complex molecule.

 

Peptide bond, Peptide linkage

Definition :-  The primary linkage of all protein structures; the chemical bond between the carboxyl groups and amino groups that unites a peptide.

Dipole bond, Double bond

Definition :- A molecule having partial positive and negative charge separated by distance commonly referred as dipole bond .

               Example :-  H₂O , NH₃ etc .

Hydrogen bond

Definition :- A chemical bond consisting of a hydrogen atom between two electronegative atoms (e.g., oxygen or nitrogen) with one side be a covalent bond and the other being an ionic bond.