Chapter 1 Study Guide KEY

Chapter 1 Study guide
Atoms and Bonding
1. Please draw a model of an atom. Indicate the location and charge of the three
subatomic particles.
2. Please list three ways that you would change your model to more accurately reflect
an actual atom.
Electrons would be much smaller than protons and neutrons and they would be
much farther away. The whole atom would be moving. The electrons would not be
traveling in circles, they would move in a general area (cloud). (Other answers are
also possible.)
3. The following image is a model of the earth. The earth is different from this model
in many ways. If the model does not show the earth accurately, why do people use
models like this? (Please give at least two reasons.)
We use models to be able to visualize the
parts of things that are too big, too small, or
too complicated to see easily. We use models
to see the parts of these systems and how the
parts relate to each other.
4. Draw an electron dot diagram (Lewis dot) for the following elements:
a. Sulfur S with 6 dots
b. Rubidium Rb with 1 dot
c. Iodine I with 7 dots
5. One of these compounds is formed by an ionic bond, and the other is formed by
covalent bonds. Please use the space below to draw the electron dot diagrams of
the elements involved in each compound. Use your drawings to draw a conclusion
on which bond is used for each molecule. In the lines below, present your
conclusion for each molecule as well as the reasoning behind the decision.
CF4: This molecule is held together with covalent bonds. A covalent bond happens when
electrons are shared, and by sharing electrons the Carbon and Flourine atoms all achieve
stability, by gaining 8 valence electrons each. This answer should also explain using the
reasoning that non-metals are bonding together.
CaCl2: This compound is held together with an ionic bond. It is non-metal Cl atoms
bonding with a metal Ca atom. The Calcium atom loses 2 electron (making it a +2 ion) and
it is then attracted to the two -1 ions formed when the Chlorine atoms gain those lost
electrons. This attraction keeps the compound together.