Enriched BiologyName______Period______Date______

Biogeochemical Cycle Lab

Nitrogen Cycle

Part I Creating Molecular Models

Now that you have an understanding of atoms, compounds and ions, you will be able to understand how the nutrient, nitrogen (N) cycles through the ecosystem. Your group will create paper molecular models for compounds or ions that are part of the nitrogen cycle. This will help reinforce the concept that two atoms can share electrons to form a bond. Let’s begin.

Procedure:

1. Obtain the template for making several size circles. Carefully cut out each template and put aside. Write the letter ‘N’ in the large circle, ‘O’ in the medium circle and ‘H’ in the small circle.

2. Obtain (4) different color pieces of paper. Each color will represent a different atom. Write down the color that represents the atom:

Nitrogen ______

Oxygen ______

Hydrogen ______

3. Using the templates, trace and cut out (5) circles to represent Nitrogen. Set aside.

4. Using the correct template, trace and cut out (5) circles to represent Oxygen. Set aside.

5. Using the correct template, trace and cut out (3) circles to represent Hydrogen. Set aside.

6. Use the images on the power point to help you construct the following using the cut out circles:

a. N2 (nitrogen)

b. NO3- (nitrate)

c. NO2- (nitrite)

d. NH3 (ammonia)

7. Carefully tape the circles together. Once you have constructed all molecular models, answer the following.

a. Write the chemical name for each on the model.

b. What atom is found in all models? ______

c. Which is/are a covalent compound? ______

d. Why is nitrogen not considered a compound? ______

______

e. Which are ions? ______Why? ______

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f. On the ammonia model, draw in a pair of electron to show where the covalent bond is located.

8. Now show your teacher your models and answers to the questions.

9. Clean up your area. Return all materials to their appropriate location. Obtain a paper clip and clip your models together. Do not lose them. You will need them in class.

Part II Understanding the Processes of the Nitrogen Cycle

Nitrogen is very important for living things. Nitrogen is part of the proteins living things need to carry out many important life functions. Let’s learn about the cycle.

Procedure:

1. Obtain a laptop from the computer cart. What is your computer number? ____

2. Log onto the computer. Be patient and do not touch laptop as you wait for the desk top.

3. Complete the Nitrogen Cycle Webquest. Your teacher will give you the paper when you finish Part I