Subject: Physical Science
Grade Level: 9
State Standard: (II.B.6.a)
Demonstrate an understanding of how carbon atoms bond to one another as simple hydrocarbons.
OBJECTIVE: The students will be able to identify, relate, and illustrate how hydrocarbons bond.
Show students the ball and stick figure and ask them, "What do you think this object depicts?"
(Explain that it is an organic compound)
Explain that organic compounds are covalently bonded compounds that contain carbon. Tell them that a carbon atom forms four covalent bonds in organic compounds. Ask the students to, "Predict why carbon has four bonds." (They should recall that carbon has four valence electrons therefore would form four bonds.) Explain that a carbon atom that bonds with four hydrogen atoms is a hydrocarbon. Ask the students, "Do you suppose that a carbon atom can share more than one electron with another element?" Then explain that a carbon atom can form double and triple bonds as well.
At this point I will hand out the nomenclature charts. Explain the nomenclature identifying the type of bond a carbon atom possesses as well as what the different bonds look like when examining a structure of a hydrocarbon.
Show the students different names and structures of hydrocarbons and the various suffixes that relate to single, double, and triple bonds.
2. Propene (structure)
3. Octyne (structure)
Then have the students determine what type of bonds the following hydrocarbons contain:
1. Butane (structure)
4. Pentyne (structure)
The students will need to try these on their own. After a few minutes, I will have them share with their neighbor.
The number of carbon atoms as well as the bond type determines the name of the hydrocarbon. Explain how to name the organic compound based on the number of carbons and type of bond. The students will be reminded to look back at the chart provided to them regarding the prefixes and suffixes of hydrocarbons in order to identify hydrocarbons.
Guide the students through naming the following hydrocarbons as a whole class. Provide the students with the structures of the following hydrocarbons:
Then the students should try to name the following hydrocarbons based on their structures I depict for them:
The students will need to try these on their own. After a few minutes, I will have them share with their neighbor and if any questions arise I will address.
As a class draw the structure of pentene, heptane, and nonyne on the board. Let students volunteer to draw the structures on the board.
Let's form the structures of propane, propene, and propyne. Have three boys be the carbon atoms and the appropriate number of girls be the hydrogen atoms. Have the students use their arms to represent the bonds.
Now that you have illustrated the structures of hydrocarbons on paper and physically, go back to your desks and draw the structures I have listed on the board.
Have the students individually draw the structures of the following hydrocarbons: ethane, octyne, and butene.
ONE SENTENCE ANSWER -- In one sentence students need to pack as much information about carbon atoms and their bonding.
Construct the structure of the hydrocarbon assigned using marshmallows, raisins, and toothpicks. The marshmallows should be the hydrogen atoms, the raisins should be the carbon atoms, and the toothpicks will be the bonds. Give each student the name of a hydrocarbon as well as a packet containing marshmallows, raisins, and toothpicks. Every student will be given a different hydrocarbon. The student will present to the class.
Copies of Organic Notes
Packets of marshmallows, raisins, and