Chemistry Review Guide for Electrons, Bonding, and
Geometry.
The topics covered during this unit have been:
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Electrons- Energy levels, sublevels, and orbitals.
Electron Notation- How we describe and notate the electrons in a certain atom.
Valence Electrons- The electrons that actually interact with their surroundings and
participate in most bonding.
Types of bonds – The three types of bonds; Metallic, Ionic, and Covalent. The typical
properties of compounds with metallic, ionic, and covalent bonds.
Molecular Geometry- The way our molecules take shape due to their bonded and nonbonded electrons. VSEPR Model, stick and ball 3D models, shapes, and angles.
The two different covalent bonds- Polar and Non-Polar
Periodic trends- Electronegativity
Polarity in molecules- How the types of atoms in a molecule affect the molecules
polarity.
When you are studying for this unit test please remember that you have multiple resources for
help. I have posted my power points used, Khan Academy links, Podcast links/ and you have
your notes, the chemistry book, your old homework, quizzes, and your peers and I. Please
recognize the many avenues available to help yourself prepare for the test. If you have an
urgent question you can email me for answers. I am also available after class and sometimes
before. Please take time to look over the unit as a whole system, these individual concepts and
ideas about the atom and bonding all interlink. They are what create the multitude of different
types of matter around us!
I will go over the basic concepts that will be addressed in the test, but I am not going to go over
each and every detail about how to work every scenario out on this guide. I will also be linking
some place where applicable.
Electrons
We took a close look at how electrons situate themselves around their nucleus. We learned
how there were different levels and in the levels there were even more specific sublevels. For
every electron around a nucleus there is a specific energy level, sublevel, orbit and spin
assigned to it. We use these to help us understand where electrons are around our atom and
how they will affect the way the atom interacts with other atoms and matter it comes in
contact with. We know how this looks on a Bohr diagram and also how we assign these
electrons in proper notation.
Electron notation
We have 3 different ways to notate electron around an atom
1. Orbital notation
2. Electron configuration
1s22s22p63s23p6………….
3. Noble gas configuration, remember go back to the last noble gas, not the next!!
[He]2s1
Valence Electrons
Valence electrons are the electrons that are in a incomplete energy level and that directly
affect bonding between atoms. We must always take into account these electrons when we are
creating bonds. Valence electrons often want to create an octet (full energy level) when
bonding occurs.
https://www.khanacademy.org/science/chemistry/periodic-table-trends-bonding/v/valenceelectrons
YOU MUST BE ABLE TO DRAW LEWIS DOT STRUCTURES CONTAINING THE VALENCE
ELECTRONS!!!!
Types of bonds
You will need to understand the 3 major types of bonds; metallic, covalent, and ionic. You will
need to know that metallic is like a sea of electrons surrounding the positively charged metal
cations. You will need to be able explain how ionic bonds are when an atom takes an electorn
form another, creating a positive and negatively charged ions, and that these charges then
create an attractions that bonds them together. Covalent bonds have two types, polar and
nonpolar, both of which share electrons in order to create a bonded connection. Polar is when
the electronegativity of one of the bonded atoms attracts the bonded electrons closer to it. This
attractions leads to a partial positive and partial negative charge to the atoms in the bond.
Nonpolar covalent bonds, on the other hand, have very little different in electronegative charge
and lead to a more equally shared bonding of the electrons.
http://www.khanacademy.org/science/chemistry/periodic-table-trends-bonding/v/ionic-covalent--and-metallic-bonds
http://www.nthurston.k12.wa.us/cms/lib/WA01001371/Centricity/Domain/2297/bonding7.mp
4
Remember only polar bonds lead to polar molecules, and only when there is an unequal
and/or nonsymmetrical electronegative bond(s) in the molecule.
YOU WILL NEED TO KNOW HOW SOLUBILITY, CONDUCTIVITY, MELTING POINTS AND TYPES
OF ELEMENTS DIFFER IN THESE BONDS!!!!!!!!!! Pg 193 and 195
Molecular Geometry
The way our molecules take shape due to their bonded and non-bonded electrons. VSEPR
Model, stick and ball 3D models, shapes, and angles.
You will need to understand the basic shapes such as linear, bent, trigonal planar, trigonal
pyramidal, and tetrahedral. You will also need to be able to draw the molecule with bonded
and non-bonded pairs. You will need to be able to draw lewis structure both dot and bonded
lewis structures. You will need to be able to describe why the VSEPR model creates the
different shapes in molecules. Remember bonded and non-bonded pairs (lone pairs) repulsion
creates the overall shape of the molecule!!!!