A Lesson in Physical Science about Molecular Bonds for Grade 11 Students

1. By Joshua G. Javier
Physical Science
2nd semester

2. In physics, it is the push or pull that is at
work in object/s, which only is the result or
the natural effect of objects having
interaction. But, with no interaction, there is
naturally and automatically no force at
work. Force manifests or is evident through
motion.
ADD A FOOTER
2

3. Force can drag us down or lift us up, or it
can push us to the left or pull us to the
right. In the same way, it can change the
direction of an object’s motion.
The two types of forces are contact and
non-contact force.
ADD A FOOTER
3

4. Force can drag us down or lift us up, or it
can push us to the left or pull us to the
right. In the same way, it can change the
direction of an object’s motion.
The two types of forces are contact and
non-contact force.
ADD A FOOTER
4

5. • An apple fruit falling to the ground
• Vehicles moving forward
• A girl pushing her friend’s back
• A magnet attracting iron nails and
staples
• The fan’s blade spinning in various speed
levels
ADD A FOOTER
5

6. In chemistry, there are also forces at work,
which now is applicable on elements and
not big objects. The two classifications of
force in chemistry are intramolecular force
and intermolecular force.
NOTE: Analyze the prefixes “INTRA-“ AND
“INTER-“!
ADD A FOOTER
6

7. To explain further, listen
to the following
illustration:
ADD A FOOTER
7

8. ADD A FOOTER 8

9. ADD A FOOTER 9

10. ADD A FOOTER 10

11. If the pillows are elements and
the thread and Velcro tape are
molecular bonds, which is
intermolecular and
intramolecular?
ADD A FOOTER
11

12. Upon identifying the two
classifications, which is more
stronger and weaker?
ADD A FOOTER
12

13. Hence, we can define the two classifications in
the ffg:
• Intramolecular force is the type force at work
WITHIN the two elements combined, while;
• Intermolecular force is the type of force at
work OUTSIDE the two elements joining them
with the other group of combined elements.
ADD A FOOTER
13

14. Types of INTRAMOLECULAR FORCES:
1. Ionic Bonding – is a type of bond where all
the valence electrons of an element is
donated to the other element, which
generates two opposite charged elements.
The element losses electrons and becomes
positive charged cation and the other
becomes a negative charged anion. It only
happens between a metal and a non-metal.ADD A FOOTER
14

15. Types of INTRAMOLECULAR FORCES:
2. Covalent Bonding – is the type of bond
which exists only between elements with the
same electronegativity – desire to attract or
gain more electrons, called electron affinity. The
higher the electronegativity, the higher the
electron affinity and vice versa. It happens
between two or more non-metals.ADD A FOOTER
15

16. The two types are:
• Non-polar covalent bonding – is the type
of covalent bond which happens between
elements with almost similar electron
affinity and if the difference of the
electronegativity between two elements
is lower than 0.5.
ADD A FOOTER
16

17. The two types are:
• Polar covalent bonding – is the type of
covalent bond which happens between a
high and a low electronegativity and if
the difference of the electronegativity
between two elements is between 0.5 to
1.9.
ADD A FOOTER
17

18. 3. Metallic Bonding – is the type of bond
which occurs in pure elemental metals like
gold, aluminium and bronze, in a sea of
electrons and permanent positively charged
ions, where electrons are freely to move in
different positive ions making it a good
conductor of heat and electricity.
ADD A FOOTER
18

19. 1. Dipole-dipole interactions – is the
type of intermolecular force that
happens between a partially positive
charged element and a partially
negative charged element, or simply
between two polar covalent bonds.
ADD A FOOTER
19

20. 2. Hydrogen bonding – is the type of
intermolecular force that happens only
between hydrogens that are
intramolecularly bonded with Fluorine,
Oxygen and Nitrogen. The positively
charged Hydrogen is attached to the
partially negatively charged Fluorine,
Oxygen or Nitrogen.ADD A FOOTER
20

21. 3. London-dispersion forces – is the
type of intermolecular force that
happens in all types of bonding,
whether ionic, covalent – polar or non-
polar. The higher the electron that the
molecule has, the stronger is its
London-dispersion forces.
ADD A FOOTER
21

22. Hence, HOW DOES
INTERMOLECULAR FORCES
DESCRIBE THE PHYSICAL
PROPERTIES OF A MOLECULE LIKE
MELTING POINT, BOILING POINT
AND DENSITY?ADD A FOOTER
22