Physical science

1. LESSON 3
POLARITY OF
MOLECULES
SENIOR HIGH
SCHOOL PHYSICAL
SCIENCE

2. OOTD: OBJECTIVES OF THE DAY!
At the end of this lesson, you should be able to:
1. define electronegativity;
2. find the electronegativity of elements in the
periodic table;
3. distinguish between polar and non-polar
molecules;
4. relate the properties of molecules to its
polarity and its application and importance
in our daily life.

3. INTRODUCTION
Molecule
- Is a group of
two or more
atoms held
together by
chemical bonds.

4. EXAMPLE OF MOLECULES
WATER SALT OZONE NITROGEN

5. EXAMPLE OF MOLECULES
ETHYL ALCOHOL ISOPROPYL ALCOHOL SUGAR COFFEE

10. LAW OWN PAY AIR
LONE PAIR

11. PAW LIAR BANE END
POLAR BOND

12. ELECTRONEGATIVITY

13. NOON FOE LARD BOON AND
NON-POLAR BOND

14. MOLECULAR

15. POLARITY
• It refers to the distribution of electric charge
around atoms, chemical groups or
molecules.
• It is a physical property of compounds which
relates other physical properties such as
melting points, solubility, and intermolecular
interactions between the polarity of a
molecules.

18. Symbolized as X where there is the tendency for an
atom of a given chemical element to attract shared
electrons when forming chemical bond.

19. POLARITY OF MOLECULES

22. Non-polar covalent bond
- A covalent bond having equal sharing of electrons
that distributes the charges evenly and cancels out.
- Cannot expect positive and negative charges if
shared electrons are equal in number and in charge.
- Thus, this result to a symmetrical structure of
molecule.
Ex. Atmospheric gases- N, O, H
Halogens – Fl, Cl, Br

24. BOND POLARITY
• ELECTRONEGATIVITY (EN)
• It is the measure of relative tendency of an
atom to attract electrons to itself when
chemically combined with another atom.
• It is the measure of relative tendency of an
atom to attract electrons to itself when
chemically combined with another atom.

27. EXAMPLE
Direction: Predict whether the bond type between the following
pairs of atoms will be ionic, polar covalent, or nonpolar
covalent.
1. C and Cl
2. Mg and O
3. H and Cl
4. N and N
5. K and F

28. MOLECULAR POLARITY
For polyatomic molecules, both the
bond polarity and molecular shape
determine the overall molecular
polarity.
Ex. H2O, CCl4, NH3 and CO2

29. In terms of molecular geometry, the
valence shell electron pair repulsion
(VSEPR) theory would help us to
determine the spatial arrangement of
atoms in a polyatomic molecule.