Mighty Molecule Building             Name ________________

                                                                                       

Most atoms are unstable by themselves and so they bond with other atoms in certain patterns in order to get stable. Of the 92 natural elements, only about 25% are important to living things and only four elements make up about 95% of living things. If you can understand how these fabulous four elements bond in order to get stable, then youcan comprehend a great deal about the chemistry of all living things.

The Fabulous Four

Element

Symbol

Color

Bonds to Get Stable

Hydrogen

H

Yellow

1

Oxygen

O

Red

2

Nitrogen

N

Light Blue

3

Carbon

C

Black

4

 For each molecule, you will be given it's common name and  the number and type of each atom in the molecule. Your job as a group to put the atoms together in a way that will form a stable molecule.   When you think  you have constructed a stable molecule, predict what you think the formula of the molecule should be and draw a sketch of the molecule. The formula should include the symbol off each element and the number of atoms of each element in your molecule.

You are now ready to build some of the most important molecules on our planet.   Remember, in order for the molecule to be stable, it must form the proper number of bonds.   When you build the molecules, use sticks or springs to represent the bonds. You can form one bond (single) between two atoms or two bonds (double) and sometimes even three bonds (triple). In these cases, you need to use the springs to show the bonds because they can bend. If you have any empty holes left in any of the atoms, then the molecule will not be stable.

Procedure:   Build the following molecules using the ball and stick models and then predict the formula for the molecule and draw a sketch of the molecule.

Name of Molecule Atoms in Molecule Predicted Formula  Sketch of Molecule
Water 2 Hydrogen

1 Oxygen

   

 

 
Ammonia 1 Nitrogen

3 Hydrogen

 

 

 

  

 

 

 

Name of Molecule Atoms in Molecule Predicted Formula  Sketch of Molecule
Carbon Dioxide 1 Carbon

2 Oxygen

 

 

 

  

 

 
Methane (natural gas) 1 Carbon

4 Hydrogen

   

 

 
Oxygen (as found in air) 2 Oxygen    

 

 
Nitrogen (as found in air) 2 Nitrogen    

 

 
Wood Alcohol 1 carbon

4 Hydrogen

1 Oxygen

   

 

 

Guiding Questions: 

1.     Do all the molecules contain only single bonds?  Why do you think this is the case?

2. Do all the molecules have the same shape? Why do you think this is the case?

3.  Because carbon (black) is the only element that can form long chains by bonding to itself over and over, it is the backbone element of all living things. What is unique about carbon that allows it form these big chains?

4. Three of the molecules (methane, propane and wood alcohol) that you made are used by people to as a fuel (for energy) What do each of these molecules have in common?