This is a chemical bonding template, so you can download and use it for free.

1. Chemical Bonding
A Lecture Presentation
Introductory Chemistry
Mr. Sanchez

2. Lecture Guidelines
1. Be prepared: You should have your notes sheet, a pencil, and a
highlighter on your desk.
2.Be polite: Listen respectfully to the lecture. This is not an appropriate
time to talk with your classmates.
3.Be a participant: Ask questions about the lecture material and make
connections between things you're learning and things you already
know. This will help you to remember the information later on!

3. Quick Review
Who remembers some of the key concepts you learned
regarding atomic structure? For this lecture, you should
know the meaning of the words...
• Atom
• Element
• Atomic Number
• Electron
• Electron Cloud

4. Electron Shells
Remember that every atom has a certain
number of electrons, which orbit the nucleus
in the electron cloud.
These electrons orbit in different energy
levels, which are known as electron shells.
The first shell can house two electrons, and it
must be full before any electrons can move to
the next shells, which can house eight
electrons each.

5. Check for Understanding
1. Which element is depicted in the
diagram to the right?
2. How many electron shells are
pictured in the diagram?
3. How many electrons are in the
outermost energy shell?

6. Lewis Dot Diagrams
In chemical reactions, the electrons in
the outermost shell are the most
important. We can represent elements
using Lewis dot diagrams, which
visually emphasize those electrons
over the others.

7. Valence Electrons
The electrons in the outermost shell of an
atom are known as valence electrons. In
the Lewis dot diagram to the left, you can
see that beryllium has two valence
electrons. How many valence electrons do
you think hydrogen has? How many does
oxygen have?

8. The Octet Rule
Partially-filled electron shells are unstable, so all
atoms ‘want’ to fill their electron shells
completely. Since most shells can hold eight
electrons, this phenomenon is known as the
Octet Rule. Atoms fulfill the Octet Rule by
forming bonds with other atoms.

9. Check For Understanding
Hint: Take a look at the periodic table if needed.
As an example, fluorine has nine electrons and seven in its
outermost shell. It will need one more electron to fill its octet.
How many electrons would carbon need to fill its octet? How
many would sulfur need? And xenon?

10. Chemical Bonding
When atoms form bonds with other atoms, it is known as chemical
bonding. Atoms will form chemical bonds with each other in order
to fill their electron shells and gain stability. Some elements have
atoms with the ideal number of electrons needed by others. This
makes certain pairs of elements more compatible for bonding.
There are two main types of chemical bonds: ionic and covalent.

11. Ionic Bonds
Some atoms need to lose electrons, whereas others need to gain
electrons in order to be stable. If the atoms are compatible, they will
engage in an ionic bond to accomplish these goals.
Ionic bonds take place when one atom ‘steals’ the
electron(s) of another atom, resulting in stability for
both atoms.

12. Ionic Bond Example
Na Cl
Sodium has one valence electron and chlorine has
seven. Sodium can become stable by losing its
single valence electron and dropping down to the
previous (and complete) energy shell, whereas
chlorine can become stable by gaining one more
electron and filling its outermost shell. These atoms
can form an ionic bond in which chlorine ‘steals’
sodium’s single valence electron, creating stability
for both atoms.

13. Covalent Bonds
Some atoms may have a number of electrons such that gaining or
losing enough to fulfill their octets is challenging. These atoms may
engage in covalent bonds instead of ionic bonds.
Covalent bonds take place when, rather than taking or
giving electrons, atoms share their electrons in order to
fill their energy shells.

14. Covalent Bond Example
Cl Cl
Chlorine has seven valence electrons and
therefore needs one more in order to fill
its octet. In the absence of any other
element, chlorine atoms can bond with
other chlorine atoms. Both atoms will
share one electron, thereby completing
their electron shells.

15. Now let’s practice
what we’ve learned!
Any Questions?

16. Resource Page