This document discusses Lewis notation and molecular structure. It describes how Lewis notation uses dots and crosses to represent valence electrons and the chemical symbol to represent the nucleus and core electrons. Examples of representing common molecules like H2O and HCN using Lewis notation are provided. It also discusses Couper notation, which only shows electrons involved in bonds. Dative covalent bonds are described as involving a Lewis base electron donor and Lewis acid electron acceptor. Various examples and checkpoint questions are used to illustrate these concepts.

1. LEWIS NOTATION
AND
MOLECULAR STRUCTURE
JOHNEL V. ESPONILLA

2. LEWIS NOTATION

3. LEWIS NOTATION
It uses dots and
crosses to
represent the
valence electrons
on different atoms.
The chemical symbol
of the element is
used to represent
the nucleus and the
core electrons of the
atom.

4. LEWIS NOTATION

5. LEWIS NOTATION

6. LEWIS NOTATION

7. LEWIS NOTATION Simple
molecules
Represent the molecule
H2O using Lewis notation

8. LEWIS NOTATION Electron
configuration

9. LEWIS NOTATION Represent
the
molecule
H2O using
Lewis
notation

10. LEWIS NOTATION Molecules
with multiple
bonds
Represent the molecule
HCN using Lewis notation

11. LEWIS NOTATION Electron
configuration

12. LEWIS NOTATION Represent
the
molecule
HCN using
Lewis
notation

13. LEWIS NOTATION Atoms with
variable
valences
Represent the molecule
H2S using Lewis notation

14. LEWIS NOTATION Electron
configuration

15. LEWIS NOTATION Represent
the
molecule
H2S using
Lewis
notation

16. COUPER NOTATION

17. COUPER NOTATION
Only the electrons
that are involved in
the bond between
the atoms are
shown.
A line is used for
each covalent bond.

18. COUPER NOTATION
Using Couper notation, represent a
molecule of water and a molecule
of HCN.

19. COUPER NOTATION
Molecule of
water

20. COUPER NOTATION
Molecule of
CHN

21. DATIVE COVALENT BONDS
a.k.a coordinate
covalent bond is a
description of
covalent bonding
between two
atoms
Lewis base – an
electron donor
Lewis acid – an
electron acceptor

22. DATIVE COVALENT BONDS
Ammonium
ion (NH+
4)

23. CHECKPOINT!
1.REPRESENT EACH OF THE FOLLOWING
ATOMS USING LEWIS NOTATION:
a.Beryllium
b.Calcium
c.Lithium

24. CHECKPOINT!
2. REPRESENT EACH OF THE FOLLOWING
MOLECULES USING LEWSI NOTATION:
a. Bromine gas (Br2)
b. Carbon dioxide
3. Which of the two molecules listed above
contains a double bond?

25. CHECKPOINT!
4. Two chemical reactions are described below.
• Nitrogen and hydrogen react to form NH3
• Carbon and hydrogen bond to form a molecule of
CH4 for each reaction, give:
a. The valency of each of the atoms involved in the
reaction
b. The Lewis structure of the product that is formed

26. CHECKPOINT!
4. Two chemical reactions are described below.
• Nitrogen and hydrogen react to form NH3
• Carbon and hydrogen bond to form a molecule of
CH4 for each reaction, give:
c. The chemical formula of the product
d. The name of the product

27. 5. A chemical compound has the following Lewis
notation:
a. How many valence electrons does element Y have?
b. What is the valency of element Y?
c. What is the valency of element X?
d. How many covalent bonds are in
the molecule?
e. Suggest a name for the elements
X and Y?

28. ELECTRONEGATIVITY
JOHNEL V. ESPONILLA

29. ELECTRONEGATIVITY
It is a measure of
how strongly an
atom pulls a
shared electron
pair towards it.

30. ELECTRONEGATIVITY

31. ELECTRONEGATIVITY

32. ELECTRONEGATIVITY
HBr?

33. ELECTRONEGATIVITY
H2?

34. TYPES OF COVALENT BONDS
Non-polar bonds
occur between two
identical non-
metals atoms.

35. TYPES OF COVALENT BONDS
Polar covalent bond is
formed where one
atom will have a
slightly negative
charge and the other
a slightly positive
charge.

36. CHECKPOINT!
1. In a molecule of hydrogen chloride,
a. What is the electronegativity of hydrogen?
b. What is the electronegativity of chlorine?
c. Which atom will have a slightly positive charge
and which will have a slightly negative charge in
the molecule?
d. Is the bond a non-polar or polar?

37. CHECKPOINT!
2. Complete the table below:
Molecule Difference in electronegativity
between atoms
Non-
polar/polar
H2O
HBr
F2
CH4