Polarity of Molecules

Physical Science - Quarter 1 - Lesson 3

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

4. INTRODUCTION
•Moleculeis a group
of two or more
atomsheld
together by
chemical bonds.

5. EXAMPLE OF MOLECULES
WATER SALT OZONE NITROGEN

6. EXAMPLE OF MOLECULES
ETHYL
ALCOHOL
ISOPROPYL
ALCOHOL
SUGAR COFFEE

8. HOW TO PLAY?
Read the group of unrelated words and
solve them into real words/phrases
before time runs out.

12. GUESS THE GIBBERISH #1
LAW OWN PAY AIR

13. GUESS THE GIBBERISH #2
PAW LIAR BANE END

14. GUESS THE GIBBERISH #3
EEL LEAK TRUE NEED GOT THIEVES
BEAT TEA

15. GUESS THE GIBBERISH #4
NOON FOE LARD BOON AND

16. GUESS THE GIBBERISH #5
MALL LET CURE LIAR
JAWMEETTHREE

17. LIST OF IMPORTANT TERMS
1.Lone Pair
2.Electronegativity
3.PolarBond
4.Non-PolarBond
5.Molecular Geometry

18. POLARITY
•Itreferstothedistributionofelectriccharge
aroundatoms,chemicalgroups,ormolecules.

19. 2 FACTORS THAT DETERMINE THE
POLARITY OF MOLECULES
1.Thepolarityofthebondsbetweenatoms
whichcanbestudiedbasedon
electronegativity.
2.Thegeometricalshapeofthemolecule
whichcanbepredictedviathevalenceshell
electronpairrepulsion(VSEPR)theory.

20. POLARITY OF MOLECULES
•Allcompoundscanbeclassifiedbasedonwhattypeof
chemicalbondformedwhentheatomscombined.
•Theclassificationofthecompoundcanbeusedto
determinewhetheramoleculeispolarornon-polar.
•Thetwoclassificationsofcompoundsarecovalentand
ionic.

21. COVALENT AND IONIC
•CovalentCompoundisamoleculeformedbycovalentbonds,
inwhichtheatomsshareoneormorepairsofvalence
electrons.
•IonicCompoundsaremadeupofionsratherthanmolecules.
Insteadofsharingelectronsincovalentbonds,ionic
compoundatomstransferelectronsfromoneatomto
anothertoformanionicbondthatreliesonelectrostatic
attractiontokeeptheatomstogether.

22. BOND POLARITY
•ELECTRONEGATIVITY (EN)
•Itisthemeasureofrelativetendencyofanatomtoattract
electronstoitselfwhenchemicallycombinedwithanother
atom.
•Thehigherthevalueofelectronegativity,themoreittends
toattractelectrontowarditself.

24. ELECTRONEGATIVITY DIFFERENCE
DIFFERENCEIN
ELECTRONEGATIVITY
TYPEOF COMPOUND
(BOND POLARITY)
Greater than
or equal to 1.7
IONIC
O.5 –1.6
COVALENT
POLAR
Less than 0.5 NON-POLAR

25. EXAMPLE
1. Predictwhetherthebondtypebetweenthefollowingpairsof
atomswillbeionic,polarcovalent,ornonpolarcovalent.
1.CandCl
2.MgandO
3.HandCl
4.NandN
5.KandF

26. MOLECULAR POLARITY
•Forpolyatomicmolecules,boththebond
polarityandmolecularshapedeterminethe
overallmolecularpolarity.
H
2O, CCl
4, NH
3and CO
2

27. MOLECULAR POLARITY
•Intermsofmoleculargeometry,thevalence
shellelectronpairrepulsion(VSEPR)theory
wouldhelpustodeterminethespatial
arrangementofatomsinapolyatomicmolecule.

28. SHAPES UNDER VSEPR THEORY