Developing in-class Activities Focused on High-level Cognitive Skills
Freshman/Sophomore Level Course
Junior/Senior Level Course
Flipping the classroom provides a dynamic and interactive
learning environment where the educator guides students
as they apply concepts and engage creatively in the
subject matter
Common concerns of flipping the classroom:
• My students will not read the book or watch the
video before lecture.
• My students would rather listen to me lecture.
• It sounds difficult.
What kind of in-class activities do I use in my lower
and upper level classes?
LECTURE (25 min)
ACTIVITY (50 min)
Lewis Symbols
Electrons are shared or transferred between atoms in chemical
bonds.
Valence Electrons – the electrons involved in bonding.
The outer shell electrons.
Lewis Symbols
• G.N. Lewis developed a simple way to
show valence electrons of an atom
• Consists of the element’s chemical
symbol plus a dot (•) for each valence
electron.
Example: Sulfur (6 valence electrons)
Carbon (4 valence electrons)
e- configuration = [Ne]3s23p4
e- config. = 1s22s22p2
Lewis structure =
Lewis structure =
# of valence electrons
Lewis Symbols
Example: Sulfur (6 valence electrons)
e- configuration = [Ne]3s23p4
Lewis structure =
Carbon (4 valence electrons)
e- config. = 1s22s22p2
Lewis structure =
Octet Rule
Atoms tend to gain, lose, or share electrons until they are
surrounded by eight valence electrons.
An octet of electrons tend consist of
full s and p subshells in an atom = ns2np2
Lewis Structures
• Formation of covalent bonds can be depicted with Lewis structures
• These depict each electron pair shared between atoms as a line and
show unshared electron pairs as dots.
• Each pair of shared electrons constitutes one chemical bond.
Drawing Lewis Structures
Practice, practice, and practice
Follow the procedure:
1. Sum the valence electrons from all the atoms.
Remember the periodic table can help you determine the number of valence electrons in
each atom. For an anion, add one electron to the total for each negative charge. For a
cation, subtract one electron from the total for each positive charge.
2. Write the symbols for the atoms, show which atoms are attached to
which, and connect them with a single bond.
Chemical formulas are often written in the order which the atoms are connected in a
molecule or ion. For polyatomic ions and molecules, the central atom is usually written
first.
3. Complete the octets around all the atoms bonded to the central
atom.
4. Place any leftover electrons on the central atom.
Do this even if so results in more than an octet of electrons around the atom.
5. If there are not enough electrons to give the central atom an octet,
try multiple bonds.
Use one or more of the unshared pairs of electrons on the atoms bonded to the central
atom to form double or triple bonds.
Table of Geometries
Thank You!