Now that the rocks are broken down, the teacher will give students their next task "Can you separate all of the 'minerals' in the mock rock?" Students will believe they can and they will start to separate the materials that they can see. In the end, they will have 4 groups of "minerals": sand, oyster shells, gravel.
2 Direct Instruction
The teacher will ask them if they think they have ALL of the ingredients separated. The teacher will guide the students to think about the sand and how many things could make that up.
The teacher will ask how they could separate the materials. After students discuss, the teacher will guide the students to the idea of mixing the materials with water and how that will separate the materials. The class will conduct the experiment with their samples of rock. Students will put a sample of the sand into a vial and add water. They will shake up the mixture and let it set overnight.
After the mixture has settled (usually overnight), students will discuss what they see. They will see more "minerals" such as the sand, more gravel, and flour. They will see that the water has turned green and can determine another "mineral" is green food coloring.
The teacher will ask again "do you think we have found ALL of the minerals?" The teacher will present an experiment to the students. She/he will hold up a clear glass full of water and a sugar cube. The teacher will as the students what will happen when I put the sugar cube into the water? Allow time for students to discuss, and then complete the experiment. Stir the cube around in the water until it dissolves.
The teacher will discuss with students if the cube disappeared or if it is still there and guide the students to say that it is still there, it is just there in a different form. "What is this called? When one substance has "disappeared" in another, it has dissolved in the other. When they come together, the mixture is now called a solution."
The teacher will ask AGAIN "do you think we have found ALL of the minerals?" Students should realize that there could possibly be a "mineral" dissolved in the water. Now their task will be to figure out how to get that mineral out.
3 Guided Practice
Students will watch the video: https://viewpure.com/OEFh1SgP6FI
When they complete the video, they will talk in their groups about the word evaporation, what it means, and how it relates to our experiment. Students will set up their experiment and predict what will happen. They will fill out the prediction form that can be accessed on Schoology and open it via Notability.
**Since we will not be heating up our trays, we will have to wait overnight for the water to evaporate.
Students will look at their trays and document what happened. A discussion will be had about the crystals that are left behind. Students will observe the crystals with a hand lense and access the Crystal Identification Key on their iPads to determine which crystals are in their trays. In the end, the students will determine that they have found kosher salt crystals as their last "mineral" from their mock rocks.
4 Independent Practice
Students will be assessed on their ability to retell the process of dissolving a material in water and evaporating the water to leave behind the crystals. Students will use Educreations to display diagrams and use their voice over to explain the process. They will access the directions on Schoology and they are also listed below.
Directions for Dissolve/Evaporate Retell:
Independently you retell the process of an object dissolving and evaporating.
Use ExplainEverything to diagram the process.
Use your voice to explain the process that you have diagramed
Export it to your camera roll
Email it to your teacher
You will be assessed on the following:
4- The diagram is clear and shows all steps in the process from the material dissolving to the evaporation and what is left.
3- The diagram shows steps in the process from the material dissolving to the evaporation and what is left.
2- The diagram is somewhat clear and shows some steps in the process from the material dissolving to the evaporation and what is left.
1- The diagram is not clear and shows few steps in the process from the material dissolving to the evaporation and what is left.
4- Voice is clear and easy to understand.
3- Voice is clear and can be understood.
2- Voice is somewhat clear and it is hard to understand
1- Voice is not clear and cannot be understood.
Students will create a Trading Card of a Solution- a liquid and a dissolved solid- that they come in contact with in everyday life (powdered lemonade, chocolate milk, ocean water). They will find a picture of the solution, upload it and describe what was dissolved. They will take a screenshot of their trading card and upload it to the album titled Solution in Schoology under Science/Earth materials/Dissolving Trading Cards.