Mix it up! Split it up! Drink it up!

Overview:

Students first get introduced to the concepts of pure substances and mixtures, and the particle theory by doing a photo-hunt for matter in their home and exploring the world of particles through images from electron microscopes. Then students design their own experiments following the scientific method to answer questions about the properties of matter. Scaffolding can be used to encourage gradual release of responsibility for choices of materials and methods. In a second activity, students are required to design and build a water purifying system using basic materials to separate the various “pollutants”, with a focus on disposal of the “refuse” of the experiment in an eco-sensitive manner.

Grade Level: 7

Strand and Topic: Understanding Matter and Energy: Pure Substances and Mixtures

Inquiry Focus:

What experiments can we do to find out about the properties of matter and mixtures? How do particles help us understand the physical characteristics of matter? How can we use our understanding of the separation of mixtures to help solve the problem of potable water?

The time required depends on students’ background knowledge, skills set, level of interest, and any additional time required for completion of student work.

Big Ideas:

Matter can be classified according to its physical characteristics. The particle theory of matter helps to explain the physical characteristics of matter. Pure substances and mixtures have an impact on society and the environment. Understanding the characteristics of matter allows us to make informed choices about how we

use it.

Overall Expectations:

Science and Technology

1. evaluate the social and environmental impacts of the use and disposal of pure substances and mixtures;2. investigate the properties and applications of pure substances and mixtures;3. demonstrate an understanding of the properties of pure substances and mixtures, and describe these characteristics using the particle theory.

Specific Expectations:

Science and Technology

1.2 assess the impact on society and the environment of different industrial methods of separating mixtures and solutions

2.1 follow established safety procedures for handling chemicals and apparatus 2.2 use scientific inquiry/experimentation skills (see page 12) to investigate factors 2.3 investigate processes (e.g., filtration, distillation, settling, magnetism) used for separating

different mixtures 2.4 use scientific inquiry/experimentation skills (see page 12) to investigate the properties of

mixtures and solutions 2.5 use appropriate science and technology vocabulary, including mechanical mixture, solution,

solute, insoluble, saturated, unsaturated, and dilute, in oral and written communication 2.6 use a variety of forms (e.g., oral, written, graphic, multimedia) to communicate with

different audiences and for a variety of purposes 3.1 distinguish between pure substances 3.2 state the postulates of the particle theory of matter (all matter is made up of particles; all

particles are in constant motion; all particles of one substance are identical; temperature affects the speed at which particles move; in a gas, there are spaces between the particles; in liquids and solids, the particles are close together and have strong forces of attraction between them)

3.5 describe the processes (e.g., evaporation, sifting, filtration, distillation, magnetism) used to separate mixtures or solutions into their components, and identify some industrial applications of these processes

3.6 identify the components of a solution (e.g., solvent, solute) 3.7 identify solutes and solvents in various kinds of solutions (e.g., copper and tin in bronze;

iodine and alcohol in iodine solution) 3.8 describe the concentration of a solution in qualitative terms (e.g., dilute, concentrated) and

in quantitative terms (e.g., 5 grams of salt in 1000 ml of water) 3.9 describe the difference between saturated and unsaturated solutions

Language: Writing

2.1 write complex texts of different lengths using a wide range of forms Language: Media Literacy

1.6 identify who produces various media texts and determine the commercial, ideological, political, cultural, and/or artistic interests or perspectives that the texts may involve

History / Geography

A3.5 describe some key natural processes and human activities that create and change water bodies and systems

B1.1 analyse interrelationships between the location/accessibility, mode of extraction/ harvesting, and use of various natural resources

B1.2 analyse natural resource extraction/harvesting and use in some specific regions of the world

B3.5 describe some responses to social and/or environmental challenges arising from the use of natural resources

Mathematics: Number Sense and Numeration

- solve multi-step problems arising from real-life contexts and involving whole numbers and decimals, using a variety of tools

- research and report on real-life applications of area measurements

The Arts: Visual Arts

D1.3 use elements of design in art works to communicate ideas, messages, and understandings for a specific audience and purpose

The Arts: Drama

B1.4 communicate feelings, thoughts, and abstract ideas through drama works, using audio, visual, and/or technological aids to heighten the dramatic experience

Key Concepts:

Pure substances, mixtures, mechanical mixture, solution, solute, insoluble, saturated, unsaturated, dilute, particle theory, scientific method

Prior Skill Sets:

steps of the scientific method (Question, Hypothesis, Experiment [Materials & Method], Observation, Analysis, and Conclusion)

use the Technological-Design Process:○ “Critical aspects of technological problem-solving are: careful planning; purposeful

selection of tools and materials; testing, retesting, and modifications of a product or process; communicating about the solution; and recommending of changes or improvements.” (Ontario Science and Technology curriculum document, 2007, p. 17)

laboratory measurements (weighing solids and liquids, measuring volumes of liquids) able to ask questions that demonstrate curiosity about what was observed can propose an answer to the inquiry and can describe steps to take to answer questions

able to recount the steps taken and share the results of an investigation in a variety of ways

Prior Knowledge:

Grade 2: Properties of Solids and Liquids

3.2 describe the properties of solids 3.3 describe the characteristics of liquid water and solid water, and identify the conditions that

cause changes from one to the other 3.4 identify conditions in which the states of liquids and solids remain constant and conditions

that can cause their states to change 3.5 describe some ways in which solids and liquids can be combined to make useful substances

Grade 5: Properties and Changes in Matter

3.1 identify matter as everything that has mass and occupies space 3.2 identify properties of solids, liquids, and gases, and state examples of each 3.3 explain changes of state in matter, and give examples of each 3.4 describe physical changes in matter as changes that are reversible

Grade 7: Heat in the Environment

3.1 use the particle theory to compare how heat affects the motion of particles in a solid, a liquid, and a gas

Materials and Equipment:

frozen liquids (ice cream, ice, Popsicles,…) various solids in powder state (sugar, table salt, Epsom salt, juice drink powder, …) various liquids (water, cooking oil, milk, orange juice, rubbing alcohol, glycerin, …) murky water mimicking polluted pond water beakers, cylinders, test tubes or the kitchen equivalent (measuring cups, measuring spoons,

glasses) scales stirring sticks weighing paper paper filters magnets sieve heating element

Safety:

Refer to your specific board guidelines and the STAO Safety in Elementary Science and Technology: A Reference Guide for Elementary School Educators (2014) (http://stao.ca/res2/unifElemSafety/ ) for the following issues:

- student allergies (p.21)- safe usage of Personal Protective Equipment (p. 34-35)- 4.2.3. Designing, Building, and Testing Constructions (p.73-76)- 4.3.1. Using Specialized Equipment (including glassware) (p.77-81)- 4.3.2. Chemicals (p.82-85)- 4.3.3. Heating and Burning (p.86-90)

Instructional Planning and Delivery:

Engage -> Explore -> Explain -> Extend -> Evaluate

Type Structured or Directed

Guided Coupled Open or Full

Participant Teacher Initiated and Performed

Teacher Initiated, Students Performed

Teacher Initiated Student Initiated

Path to Inquiry

Accommodations and Modifications

Teacher Tip: This inquiry activity lends itself to allowing a wide range of learners to access the curriculum in a variety of ways. Nevertheless, the teacher should recognise that students can have a wide variation of abilities and should ensure that instruction is tailored according to individual needs and preferences. Within this document, there are several different entry points for students along the inquiry process. Teachers can choose to do one of the options (guided, coupled, open) with the entire class or choose to do different options with groups of students depending on student ability.

Engage (I SEE)

Teacher Directed Student Directed

Activity 1: Photography Safari

To introduce the unit and review the concepts of state of matter, students take pictures of solids and liquids (gases are a challenge, but possible) found in the kitchen and bathroom. Pictures can also be found in magazines made available by the teacher. The teacher can also add a few pictures from school to ensure that both pure substances and mixtures in different states are represented.

In small groups, students try to classify images in a system that makes sense to them; they should be able to justify their choices. A shared document or image management app, such as Picasa, or a collaborative tool like Padlet, could be used by students to sort the images. You may find that they choose classifications by what appears “natural” or “chemical” to them.

It is important to spend time on terminology since such terms as “natural”, “chemical”, and “pure” do not have the same meaning in science as in popular media. The teacher introduces new terminology (such as pure substances, mixtures, mechanical mixtures, solutions). For example, the teacher can note that mixtures may have more than one component/ingredient.

Teacher Tip: Looking at labels can be a great opportunity for a media literacy unit: debunking labels. Language Curriculum, grade 7, Media Literacy: Production Perspectives 1.6 identify who produces various media texts and determine the commercial, ideological, political, cultural, and/or artistic interests or perspectives that the texts may involve.

Indigenous Perspective: When engaging students in classifying matter, the teacher can integrate the indigenous view of the four elements.

Activity 2: Seeing Particles

To introduce the particle theory principles, the teacher can ask what could be seen if we could magnify the substances in the pictures. In class, there may also be some substances to be looked at under the microscope (milk, orange juice, mud, playdough) or magnifying glass (sand, whole wheat flour). Images taken from electron microscopes can be made available. See for example:

Turk, V. (2015, March 11). This Microscope Can See Down to Individual Atoms. Retrieved from: http://motherboard.vice.com/read/this-microscope-can-see-down-to-individual-atoms

[nature video] YouTube,. (2015). Have you ever seen an atom? Retrieved 28 July 2015, from: https://www.youtube.com/watch?v=yqLlgIaz1L0

[IBM] YouTube,. (2015). A Boy And His Atom: The World's Smallest Movie. Retrieved 28 July 2015, from: https://www.youtube.com/watch?v=oSCX78-8-q0

Note that with the new definitions and the particle theory principles, the teacher and students can now classify the substances as pure substances and homogeneous mixtures (solutions) and mechanical

mixtures in a classification grid, and enact the various types and states of matter using skits where students are particles. This can be used as assessment for learning.

Questioning (I WONDER)

Throughout the process of sorting the different substances in the photo-safari, and the introduction to particles, the teacher and students can gather questions about substances that can be shared in a knowledge building circle (refer to www.knowledge-building.org). The questions can be posted on chart paper or shared online through a class-wiki or a shared document, for example. By knowing which questions will be addressed in the following section (EXPLORE), the teacher can lead and reformulate some student questions to bridge to the next step.

Example of questions that can arise during the activities:

Teacher-led Student-led

How were those substances made?How are substances extracted?Do we all use the term “pure substances” in the same way?How are the particles in a pure substance?How are the particles in a mixture?If something melts, is it the same substance?If you mix two substances together, can you always separate them?What happens to the total mass when you mix two substances together? And what happens to the volume?What are the most efficient ways to mix things together faster?

What is in the food and beauty products we use?Are chemicals bad?Are organic products better than regular ones?Is there only water in tap water?Is something “natural” better than something “chemical”?Can anything be mixed together and, if not, then why not?How can someone make a solution of solids?How could I separate the different metals in jewelry?

Explore / Inquiry activity: (I DO)

Students explore some of the basic concepts of particle theory and mixtures through the scientific method. The teacher may review the scientific method with the interactive tools in the Student Support Resources section below.

http://studyjams.scholastic.com/studyjams/jams/science/scientific-inquiry/scientific-theory-and-evid.htm

http://studyjams.scholastic.com/studyjams/jams/science/scientific-inquiry/scientific-methods.htm

The goal is to have the students design their own experiment to answer a scientific question. Below are some of the questions, with their attached concepts, that may be asked of students. It is a more powerful learning process if the questions come from the students, but it is not always possible to predict what they will ask.

Teacher Tip: The teacher can introduce the concept of solvent and solute by making juice with juice crystals, or by letting students search for definitions and have students share them with the class with their own edible examples.

Activity 1: Experimental Inquiry

Examples of questions and connected concepts;

Question Concept

What happens to the mass of a solid when it melts?

Does a Freezee weigh the same when frozen as when it is thawed? Why?

Conservation of mass

What happens to the total mass of a solution when you dissolve a solute in a solvent?

Does “juice” weigh the same as the total weight of the crystals and the water we used to make it?

Conservation of mass

What happens to the total volume of a solution when you dissolve a solid in a liquid?

Does salty water take up the same space as the total space of the salt and the water we used to make it?

There is empty space between particles

How much of a solute can you dissolve in a Saturation

solvent?

Is there a maximum amount of juice crystal you can dissolve in a glass of water?

Can solutes be dissolved in all liquids?

Can salt be dissolved in all liquids like water, canola oil, rubbing alcohol, glycerin?

Solubility

How can you dissolve a solute faster in solvent?

How can I dissolve sugar in coffee faster?

Factors that influence the rate of solubility (stirring, heat, surface area)

Particles are always in motion

Teacher Tip: When choosing materials, there are typical choices like ice/water and salt. Encourage students to choose more fun materials, such as ice cream or juice crystals, for example. Just keep in mind student allergies and the solubility of various substances, and also safety issues, such as corrosive substances, or mixtures that could become toxic or release noxious gases.

Although tasting should not be allowed during an experiment, some of the “materials”, like ice cream or juice, can be set apart for sharing during knowledge building circle.

Option 1. [Guided] Teacher-led questions are the basis of labs done in class. The teacher comes up with the questions and, as a class, the materials and the method are written collaboratively, getting student input for every step. This can be done through a shared document projected in front of the class or on chart paper. Scaffolding is possible where most of the choices are done in advance by the teacher, and empty spots are left for student choices depending on the time available and the prior knowledge of the class. For subsequent questions, more liberty can be given to student choices.

Option 2. [Coupled] Teams of students choose one question that will be the basis of the lab they execute and present to the class. The team comes up with the materials and the method. A template can be given to each team with various degrees of scaffolding, ranging from pre-formulated sentences and lists of materials and action verbs to choose from, to simply having headings for each section depending on the independence, previous knowledge, and language skills of students. For each step (choosing a general method, choosing materials, writing a hypothesis), there is either a conference with the teacher, or a class-wide feedback session.

Class-wide feedback sessions can be great to keep students on track, but also for other students to get input from their peers, and for other groups to get information about the other topics before the final presentations. For example, once groups present their general method, every student may formulate

their own hypothesis for each of the 6 questions, though they will only execute one of the 6 experiments. When results are presented to the class later, everyone gets to verify their hypothesis.

Examples of templates for preparing an experiment to answer a question.

Note that the template could be created as a class as well, where students volunteer the vocabulary or sentences that could be used. It is also possible to have different groups working with different templates.

Open ended:

Question:

Hypothesis:

Materials:

Method:

With optional vocabulary to choose from:

Question: What happens to the mass of a solid when it melts?

Hypothesis:● I think● because● then I should

observe

Materials:choose from the following:

● ice● beaker● ice cream● Freezee● thermometer● water● spoon● goggles● tongues● scale● ...

Method:

● pour● stir● measure● observe● mix● take● put● shake● count● dispose

With prompted sentences:

Question: Does a Freezee weigh the same when frozen as when it is thawed? Why?

Hypothesis: I believe that ________________________________________________________If this is so, I should observe_____________________________________________when ______________________________________________________________.

Materials:

Method: ● Take ____________● Measure the ___________ with a ____________.● Let the ____________ melt.● Measure the __________ again with a ____________.

Activity 2 - Design Inquiry

Separating Mixture Challenge

Students must design a water filtering system for a sample of muddy water, mimicking polluted water from a river, pond, or lake. Note that additional garbage can be added for an additional challenge, such as metal bolts and nuts, gum wrappers, orange peels, etc.

Students must design a sorting system to separate trash into recyclables and compostables, and purify the water. They must also decide how to dispose of the elements safely. Care must also be taken in the disposing of the system itself once it is completed. For example, students should be able to take it apart to recycle most of the system without having to throw out the whole unit in the garbage. This part takes time, but can be built into the activity as an example of responsible stewardship.

Students also decide on self-selected criteria for success (Colour? Quantity? Would they actually drink it? Was the material disposed of properly? Is this system sustainable?). These ideas can be brain stormed as a class, or selected by the students and approved by the teacher on an individual basis.

In designing of the system, the teacher and student may opt for using the SPICE design process:

S-Scenario

P- Problem

I- Investigate

C- Construct

E-Evaluate

Option 1. [Guided] Students get to observe samples of the mystery water mixture. Students are given select materials for the separation of mixtures (filter, sieve, tweezers, magnet, spoon, straws, for example). They choose and justify in which order they will apply the various tools for separation.

Option 2. [Coupled] Students get to observe samples of mystery water mixture and then are given autonomy over their choices of materials, subject to teacher approval based on safety and cost. Store bought water purifying systems should not be used, though students can seek inspiration from such systems to choose elements in developing and incorporating elements in their own design. Students need to explain each step of the separation and purifying system and how it works, using appropriate terminology.

Option 3. [Open] Students choose a complex mixture they wish to challenge themselves to separate. Choices of materials are subject to teacher approval based on safety and cost.

Students need to explain each step of the separation and purifying system and how it works, using appropriate terminology.

Teacher Tip: It is possible in a classroom to have all three options available to students depending on their abilities.

Explain

Through a knowledge building circle, the class revisits the questions asked throughout the unit, always keeping in mind what the particles are doing in matter, and how the particles can explain what we see.

Students explain the result of their experiments in Activity 1 using the particle theory. Depending on their learning styles, they may choose to draw the particles, enact them by a kinesthetic skit, or explain it orally.

As the students progress through the design inquiry activity building a water purification system, they are called to explain and support their decisions through each step of the problem-solving approach. (See Technological Problem-Solving Skill Continuum p.16-18 of the Ontario Science Curriculum document). Students explain why it was designed in a certain way, how it was built, what decisions were made through the process (especially when it came to disposal), how they know if their design was successful, and what can be improved upon.

Student Support Resources:

StudyJams by Scolastics.com has multiple videos and online quizzes on the scientific method, predictions, and outcomes, such as:

StudyJams, “Scientific Theory and Evidence”. Retrieved July 15, 2015, from: http://studyjams.scholastic.com/studyjams/jams/science/scientific-inquiry/scientific-theory-and-evid.htm

StudyJams, “Scientific Methods”. Retrieved July 15, 2015, from: http://studyjams.scholastic.com/studyjams/jams/science/scientific-inquiry/scientific-methods.htm

[CrashCourseForKids], Part(icles) of Your World: Crash Course Kids #3.2 (YouTube). Retrieved July 15, 2015, from: https://www.youtube.com/watch?v=npv74D2MO6Q&list=PLhz12vamHOnaY7nvpgtQ0SIbuJdC4HA5O&index=2

[CrashCourseForKids], Hunting for Properties: Crash Course Kids #9.1 (YouTube). Retrieved July 15, 2015, from: https://www.youtube.com/watch?v=npv74D2MO6Q&list=PLhz12vamHOnaY7nvpgtQ0SIbuJdC4HA5O&index=2

[CrashCourseForKids], What's Matter? - Crash Course Kids #3.1, (YouTube). Retrieved July 15, 2015: https://www.youtube.com/watch?v=ELchwUIlWa8&feature=iv&src_vid=npv74D2MO6Q&annotation_id=annotation_2726840817

Sites which explain most of the vocabulary and concepts related to pure substances and mixtures:

eSchoolToday, “Introduction To Elements, Compounds and Mixtures”. Retrieved July 15, 2015, from: http://www.eschooltoday.com/science/elements-mixtures-compounds/introduction-to-elements-compounds-and-mixtures.html

StudyJams by Scolastics.com has multiple videos and online quizzes on matter such as:

StudyJams, “Properties of Matter”. Retrieved July 15, 2015, from: http://studyjams.scholastic.com/studyjams/jams/science/matter/properties-of-matter.htm

StudyJams, “Mixtures”. Retrieved July 15, 2015, from: http://studyjams.scholastic.com/studyjams/jams/science/matter/mixtures.htm

Related Background Resources and/or Links:

"CODE Health and Safety in Schools Project." CODE Health & Safety Project. Web. 13 July 2015.

"Knowledge Building - Inquiry Based Learning - VIDEO - LearnTeachLead.ca." LearnTeachLeadca. Web. 13 July 2015.

Extend / Redesign

Re-do certain experiments with a different method or materials to verify a new hypothesis Test the water purifying system on a different mixture Visit a water purification plant Take apart a water purification system to look at components Design a system to separate other mixtures Skype conference with a civil engineering working in the field

Evaluate (I REMEMBER)

Criteria to look for in assessment pieces:

Consistently With prompts Not yet

Can the student use the vocabulary appropriately?

Can the student justify choices of materials and method steps in the experiment?

Can the student use the particle theory to explain the results of the exploratory laboratories?

Can the student justify the choices of separation methods to purify water?

Possibilities for Assessment As/For/Of Learning:

Assessment As Learning:

contributions to the Knowledge Building and student generated questions (wiki, website, or other)

mini-conferences checklist for inquiry/experimentation skills (can be inspired by The Technological Problem-

Solving Skill Continuum p.16-18 of the Ontario Science Curriculum document)

Assessment For Learning:

classification of substances grid drawing and skits of particles showing various properties of matter and mixtures drawing, skits, or other forms of presentation expressing what particles are doing during

changes of state design drawings, annotations, and explanations of choice of materials lab book, steps in the scientific method SPICE Design checklist (Scenario, Problem, Investigate, Construct, Evaluate) - this checklist can

be done individually or during teacher conferencing so students may be re-oriented to the appropriate next steps

Self-evaluation for SPICE Model

1. Were my sketches clear enough for others to understand?

1 2 3 4 5

2. Did I include written suggestions on my rough sketch?

1 2 3 4 5

3. Did my product do what I designed it to do?

1 2 3 4 5

4. If I worked with others, how well did I cooperate?

1 2 3 4 5

5. If I worked with others, how would I rate my contribution to the product?

1 2 3 4 5

(5= My best effort; 3 = Medium; 1 = Poor effort)

Assessment Of Learning:

oral presentation or online presentation of an experimental method, results, and conclusion rubric for assessment of the finished product

Rubric for preparing the experiment:

With high degree of effectiveness

With considerable degree of effectiveness

With some degree of effectiveness

With limited degree of effectiveness

Generates an hypothesis about possible outcomes and supports it with reasons

Selects and uses equipment and materials with concern for safety

Communicates the steps of the method using precise action verbs and scientific vocabulary

Distinguishes between independent, dependent, and controlled variable, and can explain how to observe them

Rubric for the design and build of a water system:

With high degree of effectiveness

With considerable degree of effectiveness

With some degree of effectiveness

With limited degree of effectiveness

Can communicate the design through annotated drawings and explanations

Selects materials and uses tools with concern for safety

Identifies various methods of separation and can explain what the method can separate

Can identify areas of improvement and suggest ideas for redesign

Can explain the safe and eco sensitive disposal of all the components of the systems, and separated elements of the mixture

Technology Possibilities online collaboration tools (wikispace, collaborative documents, and websites) design software to draw systems (123Dapp for iPad, sketchup) cameras and integrated cameras on iPads, Chromebook, smart phones photo and image management software (Picassa web albums, Pinterest) ideas, image, and note organization tool (Padlet, Notability) PowerPoint and other presentation tools

Indigenous Connections:

When engaging students in classifying matter, the teacher can integrate the indigenous view of the four elements. See the resource, Shared learnings : integrating BC aboriginal content K-1 https://www.bced.gov.bc.ca/abed/shared.pdf for a sample lesson (An Aboriginal View of Science, p.140).

Looking at making and using mixtures, the class may invite a knowledgeable person from the local community to speak to students and demonstrate the use of natural resources (e.g., using moose brains for tanning hides, making paint, using local medicines and combinations of plants to make specific medicines, whipping soapberries to make froth).

Living water health can be addressed when building the water purification system.“The Anishinaabe and Haudenosaunee believe the earth to be their mother and therefore the waters to be like the blood that runs in our veins. From the great oceans to the underground wellsprings, the waters provide life to all living things on earth. In the spring time the waters gush as mother earth cleans herself from her long winter sleep to prepare for the hard work of bringing forth new life. Just as it is important to keep one’s blood clean for a healthy body, so too is it essential to keep the waters clean to have a healthy and sustainable earth. As explained by Tom Porter, “The water is not just water, it is sacred.“ “[...] Indigenous people believe that it is our responsibility to maintain clean water in dealing with waste management in order to maintain biodiversity. The understanding that people must ensure resources are protected for generations to come is essential to protect and sustain them.” http://www.torontozoo.com/pdfs/tic/ways-of-knowing.pdf p.80

It is also possible to address the Safe Drinking Water for First Nations Act https://www.aadnc-aandc.gc.ca/eng/1330528512623/1330528554327