Solid Materials in Water
Objectives:
 | Students will observe what happens when solids and liquids are mixed. |
| Students will prepare and separate mixtures. |
| Students will describe common physical changes in matter (size, shape, melting, freezing, dissolving) and the heat energy that accompanies some changes. |
| Students will classify common objects and substances according to observable attributes: color, size, shape, smell, hardness, texture, flexibility, length, weight, buoyancy, states of matter, magnetic properties. |
Materials:
For each student
| White construction paper |
| 1 Zip-Lock bag for each student |
For each group
| 1-Liter containers |
| 50 ml beakers |
| Basin |
| ½-Liter container |
For the class
| Popsicle sticks |
| Pieces of aluminum foil, cloth, cardboard, candy, cookie, chalk |
| Spoons of rock salt, pinto beans, rice, raisins |
| Trays |
| ¼-Liter Containers |
| Plastic spoons |
| Water |
| Paper towels |
| Transparent tape |
| Chart paper and marking pen |
| "Solid Materials Labels" |
Teacher Preparation:
| Prepare zip bags with solid materials. Make 2-3 bags containing each solid, depending on the size of the class. Prepare enough bags so that each student has one bag. Tape labels to the bags, based on the contents of each bag. |
| In the case of the particulate solids (beans, salt, raisins, and rice), put two plastic spoons of the material in the bag. With all the other materials (Popsicle stick, cookie, candy, cloth, chalk, foil, and cardboard), put two pieces of each material in the bag. |
| Make sure there is enough water in the room for each group to have a 1-liter container filled with water. |
| Prepare the evaporation dishes by taping labels on to 11 or 12 ¼-liter containers. Find a location where these containers can sit undisturbed for several days. |
| Place one of each of the solid materials in a small cup to be used as a control group. |
Procedure for Day 1:
| Review the properties of solids and liquids with the students. |
| Tell students that their job is to find out what happens when they mix solids and liquids together. |
| Hold up the labeled bags with solid material inside. Tell them that they will get a bag containing a solid material. It might be a Popsicle stick, rice, or some other familiar solid. The label tells them what is inside the bag. |
| Have students write their names on the bag they receive. Make sure they write gently and do not put a hole in the bag. |
| Discuss how to handle the bags with the students. Make sure they understand that they cannot put holes in their bags or they will not hold water. |
| Hold up bags with each of the solid materials inside. Point out that there are two or more pieces of a solid in each bag. |
| Show the class the dry solids that they will use to compare their solids after they get wet. |
| Distribute the bags to the students and have them examine their solid materials. Make sure that each student at each table has a different solid. Have them write the name of their solid material on the white construction paper and fold it into three parts. On the first part have them draw what the solid looks like now (when it is dry) and label it "Dry." Collect the sheets and save them for later use. |
| Bring one beaker and a 1-liter container filled with water to each table. Ask students to help each other pour in one beaker of water into each bag. Demonstrate to the class how to do this. Make sure they seal their bags tightly and do not open them again!! |
| Let students observe and share the results of putting water in with their solid materials for about 10 minutes. |
| Have students describe what has happened to their solids. Allow them to show their solid as they discuss the changes. Make sure an example of each solid is shown. |
| Collect the bags and save them for the next day. |
Procedure for Day 2:
| Return the bags to the children. Have students observe what has happened to their solid after sitting in water overnight. Allow them to compare their solids to the dry solids. |
| As a class, discuss the changes of the different solids. Allow students to hold up each solid/water mixture as it is discussed. |
| Tell students that their materials "changed." Discuss the meaning of the word "change." |
| Have students draw in the middle section of their construction paper what their solid looks like now. Have them label it "One Day in Water." Collect the sheets when they are finished. |
| Ask students how they might separate their mixtures. Talk to them about pouring their mixtures into a ¼-liter container and letting it sit overnight. |
| Have one student with each solid pour his/her material into the container. As this is being done, compare again the changes between the dry solids and the solid/water mixture. |
| Let the mixtures sit for 3-4 days, allowing all the water to evaporate. |
Procedure for Day 3:
| Call students to the carpet. Review the previous 2 days of the experiment. Talk to student about what they think happened to their solids. Show the solids to them one at a time, again showing the original solid so they can compare the differences. |
| Introduce the word "evaporate." Talk about what happened to each solid when the water evaporated. |
| Finish the construction paper drawings. Have students draw in the third section what their solid looks like after the water evaporated. Have them label it "After Water Evaporated." Encourage them to discuss the three stages of their solid. |
