bonds

BOND TYPE
BOND STRENGTH
MECHANISM

Hydrogen ~ 5-10 kcal/mol Formed by a hydrogen atom belonging to one polar molecule and a negatively charged atom of another polar molecule

Covalent

single

~ 80 (50-100) kcal/mol in strength

C-C is 83; S-S is 51; O-H is 110

One electron pair is shared between 2 atoms. Bond is made with electrostatic attraction between positive nuclei and electron cloud.

Covalent

double
~150 (120-170) kcal/mol in strength
C=C is 146; C=C is 146 Two electron pairs are shared between 2 atoms. Bond is made with electrostatic attraction between positive nuclei and electron cloud.

Covalent

triple
~200 kcal/mol in strength (e.g. C -triple-C) Three electron pairs are shared between 2 atoms. The bond is made with an electrostatic attraction between the positive nuclei andthe electron cloud.

Ionic 150-370 kcal/mol
Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom.

Bond is made with electrostatic attraction between cation and anion.

Electrons will live nearer at atom with high electronegativity (is especially electron hungry).

BOND TYPE	BOND STRENGTH	MECHANISM
Hydrogen	~ 5-10 kcal/mol	Formed by a hydrogen atom belonging to one polar molecule and a negatively charged atom of another polar molecule
Covalent single	~ 80 (50-100) kcal/mol in strength C-C is 83; S-S is 51; O-H is 110	One electron pair is shared between 2 atoms. Bond is made with electrostatic attraction between positive nuclei and electron cloud.
Covalent double	~150 (120-170) kcal/mol in strength C=C is 146; C=C is 146	Two electron pairs are shared between 2 atoms. Bond is made with electrostatic attraction between positive nuclei and electron cloud.
Covalent triple	~200 kcal/mol in strength (e.g. C -triple-C)	Three electron pairs are shared between 2 atoms. The bond is made with an electrostatic attraction between the positive nuclei andthe electron cloud.
Ionic	150-370 kcal/mol	Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom. Bond is made with electrostatic attraction between cation and anion.