presentation about the different types and classifications of the chemical bonds

1. Chemical bonds
Made by Amro

2. Chemical bond

4. Chemical bond
 What is meant by the term “chemical bond”?
 No simple, and yet complete, way to define this.
 Forces that hold groups of atoms together and make them function as a
unit.
 A bond will form if the energy of the aggregate is lower than that of the
separated atoms.

5. Chemical bond
 We can obtain information about the strength of a bonding interaction
by measuring Bond energy .
Bond energy: it is the energy required to break a chemical
bond

7. Covalent bonding
Interaatomic bonding

8. The Interaction of Two
Hydrogen Atoms

9.  When hydrogen atoms are brought close together, there are two
unfavorable potential energy terms, proton–proton repulsion and
electron– electron repulsion, and one favorable term, proton– electron
attraction.
 the hydrogen atoms will position themselves so that the system will
achieve the lowest possible energy; the system will act to minimize the
sum of the positive (repulsive) energy and the negative (attractive)
energy .
 The bond length is the distance at which the system has minimum
energy.
Covalent bonding

10. Covalent bonds:
H:H

11. 2-Double covalent bonds

12. 3-Triple covalent
bonds
• -note that the length of the
bonds changes as : from
longest to shortest:
• Mono>double>triple
• But the opposite in the
strength of bond as :
• Mono<double<triple

14. 2- different two
non metals by
un-equal sharing
of electrons to
achieve the
stability

16. Covalent bonds are classified into:
1. Pure covalent
2. Nonpolar covalent
3. Polar covalent
4.Dative bond(Coordinate Bond)

17. Pure covalent
• Between nonmetallic elements of similar electronegativity.
• Formed by sharing electron pairs
• Difference in electronegativity between atoms = zero
• Ex: O2 , H2 , Cl2

18. Nonpolar covalent
• Between nonmetallic elements of slightly different
electronegativity.
• Formed by sharing electron pairs
• Difference in electronegativity between atoms more than zero till
0.4
• Ex: C-H bond in CH4

19. Polar covalent
more than 0.4 and less
than 1.7
• Ex: HCl

21. 4.Dative bond(Coordinate Bond)
• In this type: the source of electrons come from an atom has a lone
pair of electrons that acts as a donor that shares its atom with
another one has vacant orbital acts as an acceptor
• It appears in the force between the water molecules like hydrogen
when surrounding the solute materials or the aqueous dissolved ions

24. The Pauling Electronegativity Values

25. • On the periodic table, electronegativity generally increases across a
period and decreases down a group.
• The range of electronegativity values is from 4.0 for fluorine (the
most electronegative) to 0.7 for cesium (the least electronegative).

27. Dipole Moment
• Property of a molecule whose charge distribution can be
represented by a center of positive charge and a center of
negative charge.
• Use an arrow to represent a dipole moment.
• Point to the negative charge center with the tail of the arrow
indicating the positive center of charge.

28. Dipole Moment

29. No Net Dipole Moment (Dipoles Cancel)

31. Ionic bonding
• when sodium and chlorine react to form sodium chloride.
• electrons are transferred from the sodium atoms to the chlorine atoms
to form Na+ and Cl-ions.
• which then aggregate to form solid sodium chloride to achieve the
lowest possible energy by behaving in this way.

32. Ionic Bond
• Formed Between atoms of metals and nonmetals with very
different electronegativity where the difference in
electronegativity between the metal and the nonmetal must
be more than 1.7
• Bond formed by transfer of electrons where :
1. Metal has large atomic radius so tends to lose its valence
electrons changing to +ve ion.
2. Nonmetal has small atomic radius tends to gain electrons
changing to –ve ion.
• Both to reach the structure of nearest noble gas.
• Examples; NaCl, CaCl2, K2O

33. Ionic Bond
The energy of interaction between a pair of ions[lattice
energy] can be calculated using Coulomb’s law in the form:
 lattice energy :The change in energy that takes place when separated
gaseous ions are packed together to form an ionic solid.

36. Thanks for listening
Made by Amro Farag