In this Cornerstone Lesson you will see that the Mystery Powders Lab is a great way to establish protocol, teamwork as well as strengthen their observational skills.
Lesson Materials and Equipment:
- Powders: Salt, sugar, epsom salt, baking soda, cornstarch, & white powdered laundry detergent.
- Liquids: Tincture of iodine, vinegar, & grape juice.
- Baby food jars (6 per group) or small glass containers
-Plastic spoons (6 per group)
- Black construction paper
- Blank overhead plastic transparencies
-Masking tape, & pens
-Plastic trays to hold the baby food jars
Prior to the lesson: I had all the materials ready to go and easily accessible for students to retrieve.The transparencies were taped in columns and rows, completely ready for students to work on. The SB file gives the instruction for students to tape and put together their testing sheets. I planned to do that, but my classroom helper prepared the testing sheets by placing the Observation Sheet behind the transparency and taped that together. That was a brilliant idea and a real time saver! The words are clearly there and students don't waste time trying to write with markers on small spaces.
I counted out spoons, placed eyedroppers out, and placed a small sheet of white paper on each table for each group to write their names on. I taped blank masking tape onto each baby food jar and placed them in rows of six. Each white powder container was set on the counter with two beakers half filled with the corresponding powder. They were placed in front of the container so the student could see the words and the packaged powder.
The Hook: I opened the lesson today by holding up a glass baby food jar and asking,"What's in this stuff?" I roved the classroom and passed it by them asking them to share some ideas about how to figure it out. After our brief discussion, I announced that we would have to perform some experiments to figure out exactly what this powder contained and that there were ways to do it!
I told them I wanted to discuss some important things we need to remember before we start a lab. I brought up LAB SB Classroom File in order to establish rules and understanding of expectations of student responsibilities during a lab. We discussed each point together. Students seemed to understand each point about safety, taking turns and was willing to accept the responsibilities. I told them that the lab was a great place to learn teamwork skills too!
I opened up Mystery Powder Lab Day 1 SB Class File and began teaching from the first page and working to establish some habits in understanding vocabulary. Each student filled out their Frayer Model Template as I guided them to discuss each word and concept. Matter, Physical Property and Chemical Property were focus words, but we also talked about physical and chemical changes. The Frayer Model was practiced because in each experiment and lesson there will be focus words.
When vocabulary was finished, I moved them into the activity and establishing roles of each team member, (SB file p. 4). This is important because they need to understand that everyone must take a role in making the experiment successful. I gave them to the count of ten to establish who would get the materials, who would return materials and how they would take turns doing the procedures.
Gopher- person who gets materials
Checker- person who checks materials and procedures.
Returner- person who returns all materials
First, students got the jars and spoons. They labeled their jars. Then, two students went to each "powder station" to fill their jars. Then, the Checker made sure that the powders were correctly labeled and placed in the correct jars. As this transpires, students support each other in their jobs. Everyone should be busy.
After students got their stations all set up. I passed out their testing and procedure sheets. I explained each section and how each sheet is used in the experiments, (SB file p. 5).
I explained what an "indicator" is and we talked about chemical changes very briefly. I wanted the focus to be on procedure, observation and not on the meaning of chemical change. I wanted them to be aware that the powders would change chemically and they could tell by observing physical properties. We reviewed the importance of using precise language, ( SB file p. 6). As we talked about it, gave them examples of improper scientific words and they affirmed that "awesome", "cool" or any word that was an opinion or a vague word would not be appropriate to describe science.
It was time to begin! Groups double checked our materials by using SB file slide 7.
As I continued to teach the lesson, I moved the Mystery Powder Lab Day 1 SB Class File to page 7 and passed out the beakers filled with the grape juice indicator liquid. I demonstrated what two drops looked like so that I could help them understand exactly how much liquid to drop onto the powders. If I didn't do this, there could be a real mess with grape juice.
Students began to set up their first test by locating the indicator test on the sheet. I demonstrated what a pinch of the powder looked like. The groups took turns setting up the first test by repeating what I had done. I roved the class checking that groups had their sheets set up correctly. As I roved I noticed the words they were using for their observations. I was looking for precise descriptions. As I noticed that some students were using words that were more vague, I guided them to find better, more accurate descriptions.
I questioned what was happening with each powder as they dropped the indicator on the testing sheet. I explained that this was the test that would help them make a prediction about the other chemical changes/reactions. I explained that they were describing physical properties.
When they finished the first test, I instructed them to drop water on a row of powders and recorded what they observed. This is called the "evaporation test" on the sheet. This will sit all night and evaporate. It is for tomorrow to observe first thing. I asked if there were any color changes in any of the powders using the water. The water is somewhat uneventful in comparison to the indicator test. But, students looked on with anticipation as if it would explode. I loved it.
As soon as students were finished with setting up their evaporation test, I had them check all of their observations for the day. I asked them to be sure they had used precise descriptive words. I asked them about what they had noticed and if things surprised them. I told them that tomorrow we would start off by describing the evaporation test and that we would note any changes in the samples.