Making Models

Answer the following questions in your composition notebook.

Scenario #1 (two cups, each with a separate color model)

  1. Sketch the set up.
  2. List 3 observations.
  3. What do the plastic models represent? How?

Scenario #2 (pour one cup of models into the other)

  1. Sketch the set up.
  2. List 3 observations.
  3. Does this represent a physical or chemical change? Explain.
  4. Does this mixture represent atoms, elements, a mixture, or a compound? Why?

Scenario #3 (black with 4 holes=carbon and red with 2=oxygen)

  1. Using the longer plastic links, combine 1 carbon with 2 oxygen. Be sure not to leave any holes open.
  2. Sketch the set up.
  3. Does this represent a physical or chemical change? Explain.
  4. Does this combination represent atoms, elements, a mixture or a compound? Why?
  5. Use the information page to determine the name of this model. What is the name of this model?
  6. What is holding the atoms together in the model? What does this represent?
  7. What do the holes in the atom models represent?

Writing Chemical Formulas

  1. What are the chemical symbols for the atoms you used in the first scenario?
  2. What are the chemical symbols for the atoms you used in the second scenario?
  3. Define chemical formula. (Hint: use the textbook)
  4. For the third scenario, we use a chemical formula. Why? (Hint: use page 161 in textbook as a reference)
  5. How is a chemical formula different from a chemical symbol? (Hint: refer to today’s opening)
  6. Based on your previous answers, what is the chemical formula for the third scenario?

Finished early? Complete the Challenge below. Challenge is continued on back.

Challenge Making Models

Answer/ Complete in your composition notebook.

Model substances 1 -7. Create a table for your work, like the one on back. In the table, include the name of the substance, the chemical formula, and a sketch.

  1. oxygen - as it is found in the air we breathe (O2)
  1. water
  1. chlorine – normally found as a molecule or chemically combined with another element (Cl2)
  1. methane gas
  1. 2 salt compounds
  1. hydrogen peroxide - common medicinal chemical (H2O2)
  1. propane (used in gas grills, C3H8)

Name / Chemical Formula / # of Atoms / Molecule, Compound, or both / Sketch
1 / O2
2
3. Chlorine
4. /
5. Sodium
Chloride
6.
7.

Analysis and Conclusion – Answer the following in complete sentences.

  1. Create a pure substance (element, molecule, or compound). Sketch and color your pure substance, and explain why it is a pure substance? (Hint: page 35 in the textbook)
  1. Create a molecule with only one type of element. Sketch and color your molecule, and explain why it is a

molecule versus a compound. (Hint: notes on molecules in composition book for help)

  1. Create a compound. Sketch and color you compound, and explain why it is a compound. (Hint: notes on compounds in your composition book)
  1. Explain why your molecule could be a compound, but your compound could NOT be a molecule. (Hint: notes

on molecules and compounds in your composition book)