Phosphates

Student Objectives: Students will learn the uses of phosphates and the importance of phosphates.

Tips for the Teachers: Discuss the agriculture of your area, if any, and the importance of fertilizer to its success. Invite a guest speaker from the agriculture industry or use library resource materials to illustrate the effect of phosphates in your area.

Suggested Activities:

1. Grow plants in the classroom (may use project from Sand & Gravel). Use fertilizer in some, not in others and compare plant growth.

2. Have students make cartoon characters from various crops (corn, beans, etc.).

3. Let students make fruits and vegetables from construction paper and make a bulletin board or wall mural.

4. Help students create a bartering game. Divide class into four equal groups. Each should represent a food group (meat, vegetables/fruit, grain and dairy). Each student makes six cards for food in that group, showing the name of the food and group it is in. The object of the game is to collect at least one food from each group to make a “meal”. Foods are obtained by trading one of your foods for one from another group. This can be done by taking turns or by all trading at the same time. When the game is done, students could draw a picture of the “meal” they put together.

Measurements/Evaluation:

1. What is the largest use of phosphates?

2. Plants and animals must have phosphates to do what?

3. What parts of the human body need phosphorous?

4. Superphosphates are special because they do what in water?

 Phosphates

The name phosphate rock is given to rock that contains the element phosphorous along with other minerals. Phosphorous is one of the things that all plants and animals must have to live. When plants grow, they get phosphorous from the soil. If they die and are left to decompose, the phosphorous will go back into the soil. But when farmers grow crops, the plants become food for humans and animals. Since it is not returning to the soil naturally, phosphorous must be replaced with fertilizers. Human bones, teeth, muscles and nerves need Phosphorous. 

The large group of chemical compounds that contain phosphorous are called phosphates. By treating some of these with sulfuric acid, Superphosphates can be made. They are special fertilizers that dissolve in water so plants can use them easier. Even though the largest and most important use for phosphates is in fertilizers, there are other important uses. Some of them are in detergents, baking powder, animal feed, medicines and making materials fireproof.