Crack That Marble! Properties of Matter Labs
Lesson 4 of 12
Objective: Students will be able to identify the physical and chemical properties of substances in a reaction.
In this two day lab rotation, students obtain information from text about physical and chemical properties independently and go through a series of fun and exciting lab stations in which they must identify properties and how they are affected by thermal energy.
This lesson is designed to address the following NGSS and Common Core standards:
MS-PS1-2 Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
MS-PS1-4 Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed.
CCSS.ELA-LITERACY.WHST.6-8.1.B Support claim(s) with logical reasoning and relevant, accurate data and evidence that demonstrate an understanding of the topic or text, using credible sources.
CCSS.ELA-LITERACY.RST.6-8.4 Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 6-8 texts and topics.
CCSS.ELA-LITERACY.RST.6-8.10 By the end of grade 8, read and comprehend science/technical texts in the grades 6-8 text complexity band independently and proficiently.
Science and Engineering Practices:
When using the text strategies utilized in this lesson, students think deeply about their reading in order to draw their own conclusions and consider solutions to problems. Thus, students are using the Scientific Practice of Asking Questions and Defining Problems which states that "Students at any grade level should be able to ask questions of each other about the texts they read, the features of the phenomena they observe, and the conclusions they draw from their models or scientific investigations. For engineering, they should ask questions to define the problem to be solved and to elicit ideas that lead to the constraints and specifications for its solution." (SP1)
In preparation for performing the lab stations, students use strategies to obtain scientific information and evidence from text (SP8). In addition, students back up their explanations in the lab document with evidence from data and qualitative observations (SP7).
In identifying properties that may change in the reactions occurring at the lab stations, students can begin to see patterns in the structures of different types of matter and how properties respond to changes in thermal energy. Thus, students can begin to see that macroscopic patterns are related to the nature of microscopic and atomic-level structure (CCC Patterns).
In a previous lesson, Marshmallow Molecules, students learned to look for patterns in the way the particles of a pure element, molecule, and mixture looked. In this formative assessment, students demonstrate their understanding of classifying matter by looking at the structure of the particles.
The top of the formative assessment states, "I can recognize how the particles in an element, molecule, compound, and mixture are different." This is one of their skills. You can take a look at all of the skills for this unit in the Chemistry Unit Plan that is provided to the students. In addition, I have provided the notes page and worksheet students completed prior to this formative assessment in the resources as well.
When grading this formative assessment, I sort the slips into stacks of similar learners. For example, I might have a pile of students that do not understand that in a mixture, all of the atoms are not bonded together as they are physically mixed. Or, I have a group of students that chooses that O3 is an element and not a molecule because they have a misconception of what the subscript 3 means. I meet with these students in groups during independent work time in a future lesson.
When I provide feedback on this formative assessment in conference groups, students plot their score and then in the open area on the bottom, they add to their Working Towards Mastery List. The "Working Towards Mastery List" is a place students write the concepts or topics that they have not yet mastered or need to study more in depth. It is a way for each individual student to organize their specific feedback. Come summative assessment time, students have a clear record of not only their growth, but of the specific concepts that they missed along the way that should be the focus of their studies.
In my class, I score everything as a 1, 2, 3, or 4 (4 being mastery); thus, the y axis is labeled with these scores. However, you could place your own grading scale that represents your classroom. In addition, along the x axis, it is labeled "a, b, c, d, etc". In my gradebook, in order to organize all of my formative assessments in chronological order by skill, I have to include these; thus, I include this here. You might include assignment names or any other numbering system that would indicate time progression on the x axis.
The student below had earned a "3" on this skill for the first formative assessments and now has earned a "4", demonstrating growth. This student has written their focus topics below. In this case, the student writes, "Subscripts means there are bonds." and "In my class, I score everything as a 1, 2, 3, or 4 (4 being mastery); thus, the y axis is labeled with these scores. "O3 is a molecule not an element."
Ask students, "What are you going to learn today?". Students should respond by saying that they will be answering the Essential Question, "How do particles combine into new stubstances? And, what evidence can show how the physical and chemical properties of the substances change?" This EQ is posted on my board and on the student's Chemistry Unit Plan.
Explain that today we are going to go through a series of lab stations that will ask them to use their learning from the first three skills. However, the focus of this lesson is to introduce them to Skill 4, "I can identify the physical and chemical properties of the reactants and products in a reaction." Ask students to take some time to independently complete the following:
- Update their mastery scores for previous skills if needed. (Notice on the student example below, students self assess and rank themselves on a scale of 1 - 4 (4 being mastery) for each skill a lesson addresses.)
- Read Skill 4, underline the key vocabulary and circle the key verbs in the skill.
- Rank their initial mastery score for Skill 4.
Ask students to turn to their Skill CH.4 Notes Page and True False Statements. In my class, at this point in the year, we have been working hard on obtaining information and meaning from text. I tell my students that today's lesson is an opportunity for them to demonstrate independence with this skill. I ask students to silently read their notes page from the beginning to the middle of the second page where it says "Solutes and Dissolving". When reading students must "talk to the text" and climb the "Ladder of Discourse" (more on these strategies below). The levels of the ladder are "Tweets" (text to self connections), "Huh?'s"(questions or concepts they do not understand), "Found It" (finding answers to questions through context clues or finding science answers), and "Discourse" (combining ideas to think beyond the text).
In the student work below, notice that the student "talked to the text" to show their thought process as they read.
For a closer look at the comments students make when talking to the text and climbing the ladder of discourse, watch the video below. This will give you a close look at what the "rungs" of the "Ladder of Discourse" mean in student work.
For more background on talking to the text"and the Ladder of Discourse check out the following lessons. These lessons include videos that demonstrate these strategies and student work that results from their use.
Explain to students that they will be going through a series of lab stations that will ask them to look at the physical and chemical properties of substances as they go through reactions. (This set of labs are some of my students' favorites all year! They are so much fun!)
I always ask students to "channel their inner scientist" and thoroughly read the procedures as well as look back at the text (Skill 4 Notes Page) to look up and obtain any information they need to answer the lab questions. I explain that this is a lab of independence, both in the manner in which they will rotate and in the fact that the students will answer all questions based on their reading of the text and not based on my direct instruction. I have students rotate through the stations at their own pace in groups of 3 - 5. My students are used to lab rotations as we use them every week; if this is your student's first experience, you may want to rotate them yourself to make sure they manage their time efficiently.
Descriptions of each station are included below. There are detailed directions in the Crack That Marble Lab Directions in the resource section. I post these directions at each station.
Station 1: Crack that Marble!
Students heat up a marble in a pan on a hot plate and then place it in a beaker of ice water causing the marble to shatter!
The marbles and pan are extremely hot. Emphasize that students get their marble using tongs and not their hands. Also, they need to follow the procedure to let the marble sit in the ice water for a few minutes. The marble will still be hot! If students drop the marbles, they will shatter into pieces and marbles are made of glass.
The cheaper the marble, the better. I get mine from the local dollar store. I have purchased from Amazon before, but the nicer marbles just don't have as dramatic an effect. Marbles must get extremely hot. I put a ton of marbles in the pan before school starts so that they are all really hot by the time class starts.
Station 2: Hot Air Balloon
Students place an empty two liter bottle with a balloon on top over a hot pan and it expands. Then, they place it in an ice bucket, and the balloon deflates.
The pan is hot. Tongs must be used to hold the bottle; students will want to use their hands.
The balloon might not blow up very large; it still demonstrates thermal expansion. Stretching the balloons help.
Station 3: Wall of Air
Students try to blow a piece of paper into a two liter bottle but it blows back towards them!
If students do not use short, quick exhales, they will be able to get it in. Also, if they do not blow directly into the bottle and are at an angle, it won't work. Emphasize they must follow the directions for exhaling exactly.
Station 4: Milk Jug Transparency
Students heat a milk jug over a Bunsen burner and it turns from translucent to transparent! When cooled, it turns back!
Goggles must be worn at the Bunsen burners. If the piece of milk jug gets to the point it starts melting or "dripping" it can affect the burner. Tongs must be used to pick up the pieces of milk jug.
Take a cleaned out milk jug and cut it into slips. These slips can be reused all day. Emphasize that the milk jug slip must be held over the flame, not in the flame. Students may need a review of what transparent and translucent mean.
Station 5: Bottle Balloons
Students place Coca-Cola in a baby bottle, cover the holes in the nipple, and shake. The nipple blows up like a balloon!
Practice this yourself ahead of time. The nipples work better after a few uses when they can get "stretched out". Also, as you practice you can see the best way to hold the bottle so you can show the students. Emphasize to the group that someone with a steady hand should do this. If a student "panics" when holding the bottle and move their fingers, the pop could spray. Tell students that when they are done shaking, they should point the bottle down into a sink before removing their fingers.
Station 6: Ferrofluid
Students use different strengths of magnets to experiment with ferrofluid. It is so cool!
Keep the containers sealed. Students should not touch ferrofluid and it stains clothes.
Ferrofluid can be purchased from any online science store.
Student responses and answer keys are included in the resource section. In addition, in the reflection, I go through student work and point out some ways that this lab gave me insight into what real student mastery of concepts might look like.
As a class, ask students to share any evidence they observed of the properties of substances changing in a reaction. For each piece of evidence they share, ask them to identify the cause of the change in properties.
For example, a student might say, "The milk jug change in density because heat was added."