This document discusses different types of chemical bonds: 1) Metallic bonds form when valence electrons are delocalized and shared between all metal atoms in a lattice, holding the positive ions together. 2) Ionic bonds form when a metal transfers electrons to a nonmetal, creating oppositely charged ions that are attracted to each other. 3) Covalent bonds form when two nonmetals share valence electrons in a molecule through electron pairs. Lewis structures are used to represent electron sharing in covalent bonds.

2. A OB ND IGN S

3. A
OB N D I GN
S

4. METALLI
C
BOND
Bonding
Lewis
Dot
Diagram
Chemical Bonds and Metallic Bonds

5. • The force that holds atoms or ions together as a
unit.
**During a chemical reaction, it is the valence
electrons that actively take part in the charge.
• The electrons in the lower energy levels
usually remain unchanged
Chemical Bonding

6. • Results of a chemical bonding can form an
ion, molecules and compounds depending
to what type of bonding took place.
Chemical Bonding

7. Has two types
Ionic Bonding
Covalent Bonding
Chemical Bonding

8. Valence
electrons
Lewis Dot
Diagram
Octet
Rule

9. How many valence
electrons are there in
Chlorine?
Valence Electrons
The number of electrons in the outermost
shell; or the outermost electrons.
How many valence electrons are
there in Neon?
Cl- 1s2 2s2 2p6 3s2 3p5

10. Lewis Dot Diagram
Are simplified version of Bohr-Rutherford
model
The symbol of the element is written at the
center and has dots surrounding it which
represents the valence electrons.

11. Gilbert Newton Lewis
1990
An American chemist,
who developed Lewis
Dot Diagram
He contributed to the
development of the new
model of atomic
structure

12. Ways to write Lewis dot diagram
1.Write the chemical symbol of the element
2.Find the number of valence electrons
3.Draw the valence electrons using dot or cross
sign ( • or x )
H
•

13. Lewis Dot Structure of Chlorine

14. Octet Rule
Atoms tend to combine in such way that they each
have eight (8) electrons in their valence shells,
giving them the same electronic configuration as a
noble gas.
Molecules or ions tend to be stable when the
outermost electron shells contain eight electrons.

15. Octet Rule
Happy atom – Stable – Unreactive
Unhappy atom – Unstable -- Reactive

17. An ionic bond is fomed between
a metal and a nonmetal

18. Ionic Bond
• The transfer of electrons from one atom to another
causes electrically neutral atoms to become ions.
• The electrostatic attraction between ions of opposite charge
is called an ionic bond.
•Giving of electrons

19. Sample problem:
Draw “dot/cross” diagrams to
represent the electron transfer in
the formation of sodium oxide
and Magnesium oxide

20. Answer:
Na and O
Na
Na
O
X X
X X
X X

21. Answer:
The Lewis structure for Na and O are:
[Na]+
[Na]+
O
X X
X X
X X[ ]
2-
Sodium Oxide (Na2O)

22. Answer:
Mg and O
Mg O
X X
X X
X X

23. Answer:
[Mg] O
X X
X X
X X
The Lewis structure for Mg and O are:
[ ]2+ 2-
Magnesium Oxide (MgO)

24. Seatwork:
In each of the following cases, the ratio in which the
ions combine is given. Show the transfer of electrons
and write the chemical formula of ionic compounds that
will be formed from them.
A. One Al and three Cl
B. One Ca and one S
C. Two Na and one O
D. One Ba and two Br
E. One Ca and two Cl

26. A covalent bond is formed between
two non metals

27. Covalent Bonds
• Covalent bonds result when two positive nuclei attract the same
electrons, thus holing the two nuclei close together.
• When two or more atoms share electrons through covalent
bonds, a single, electrically neutral unit called a molecule is
formed.
•Sharing of electrons

28. Sample problem:
Show how the NH3 was formed
after a covalent bonding. Draw
the Lewis Structure of NH3.

29. Answer:
N and 3 H
N
H
H
H

30. Answer:
N HH
H
NH3 Nitrogen trihydride (Ammonia)

31. There are two pairs in a covalent
bond
Lone pair and Bond pair
Bond pairs
Lone pair

32. Lewis structure of
Ammonia showing
shared electrons,
showing single bonds
Shared electrons can also be written using a
dash (-)

34. Seatwork:
Given the chemical formula, show the bonding of
electrons using the Lewis structure
A. H2O
B. PCl3
C. CCl4
D. SO3
E. CO2

36. Metallic Bonds
A metallic bond is pretty different from covalent and ionic bonds, but
the goal is the same: to achieve a lower energy state. Instead of a
bond between just two atoms, a metallic bond is a sharing of
electrons between many atoms of a metal element.

37. • if you can find a small piece of metal like a paper clip
or a staple. All of the atoms in that small piece of metal
are sharing a big pool of valence electrons known as
a sea of electrons or delocalized electrons. The big
pool is like a free-for-all in that any valence electron can
move to any atom within the material.
• Once the valence electrons detach from their
original atomic owners and float around in the sea,
the metal atoms become positive ions. The result is
an orderly structure of positive metal atoms
surrounded by a sea of negative electrons that hold
the ions together
like glue.

38. OBSERVATION EXPLANATION
Metals are dense
The particles in metals are tightly packed in
lattice.
Metals have high melting and boiling
points
Strong forces of attraction exist between particles.
A large amount of thermal energy is required to
overcome the strong electrical forces between the
positive ions and the delocalized electrons. These
forces operate throughout the lattice
Metals are good conductors of heat
Delocalized electrons transmit the energy of
vibrations of one positive ion to its neighbours.
Metals are good conductors of
electricity
Electrons are delocalized within the lattice.
Electrons flow in at one end and the same number
flow out the other end.
Metals are malleable and ductile
The distortion does
not
disrupt the
metallic bonding
Metals are lustrous
The presence of free electrons
causes most metals to reflect light

39. Thank you for Listening!
Prepared by: Hannah Joy Lontayao