Student Lab Sheets
Name:_________________________________________
Experiment
Added salt to
warm water until
no more salt
would dissolve.
Observations
Molecular Structures of Compounds
Day 1:
Table 1: Observations for
Part 1
Salt was dissolving into water
until it reached a point where no
more salt could dissolve.
Day 4:
Made observations
of beaker after
water has
evaporated.
Cube-like crystals appear at the
bottom of the beakers. They look
like they have the same shape as
the smaller salt crystals we added
three days ago. All the water has
evaporated.
NaCl (table salt)
Part 1 Question:
How did you make models that describe the composition of salt and water molecules?
The models were made by first looking at formulas of salt and water to find out what type and how many of each type of atom we
needed. In salt (NaCl) we needed one chlorine and one sodium. In water (H2O) we needed two hydrogen and one oxygen. We then
selected these atoms from the molecular model kit and connected them together. After we made a 3-D model we sketched a
diagram of each compound in table 1. This gave us a good idea as to the general shape and composition of salt and water.
1|Page
RIIA Teacher Guidance Document – 6th-8th Grade Task “Modeling Chemical Reactions”
Student Lab Sheets
Name:_________________________________________
Table 2: Sketches of Other Compounds
Compound
Chemical
Formula
Potassium chloride
KCl
Methane
CH4
Hydrogen
H2
Molecular Structure
2|Page
RIIA Teacher Guidance Document – 6th-8th Grade Task “Modeling Chemical Reactions”
Student Lab Sheets
Name:_________________________________________
Part 2: Sketch the model of the large salt crystal in the space below.
3|Page
RIIA Teacher Guidance Document – 6th-8th Grade Task “Modeling Chemical Reactions”
Student Lab Sheets
Name:_________________________________________
Part 3: Answer the following Final question:
Describe how atomic models were developed to describe the atomic composition of simple molecules and their crystalline structures?
In Parts 1 and 2, the simple models were made by first looking at formulas of each compound to find out what type and how many
of each type of atom we needed. We then selected the atoms from the molecular model kit and connected them together to form 3D models of each compound. After we made 3-D models, we sketched a diagram of each compound in table 1. From our models of
simple molecules were able to see the general structure and composition of each compound.
Later in Part 2, we used a model to look at how crystallization takes place. We were able to see how crystals were formed and then
construct (grow) a larger crystal structure by adding on more individual units of the molecules. That way we were able to show that
lagre crystals were made up of identical smaller molecules stacked into a pattern.
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RIIA Teacher Guidance Document – 6th-8th Grade Task “Modeling Chemical Reactions”