Top: Water Liquid, Ice Solid (Photo by StockSnap via Pixabay)

Setting the Stage

When students explore the world around them, they become aware of the many materials and substances in it, and the similarities and differences in the properties of these materials and substances including how they look, feel, and change. The categories of ‘liquid’ and ‘solid’ provide one way for students to start to organize their understanding of everyday materials and substances.

In this inquiry, students will have opportunities to deepen their understanding of the properties of materials as they observe and compare and contrast familiar liquids and solids. Their observations will help them to predict what will happen when liquids and solids are mixed together. Students will also have opportunities to investigate how safe handling of liquids and solids helps to maintain a healthy environment for all living things.

When working with liquids and solids, it is important that students do so in a manner that ensures their personal safety and the safety of others. This includes understanding why they should never put any materials in their mouths unless instructed to do so by the educator and why they should wash their hands after handling any materials.

This inquiry could begin from:

    Cover of Cloudy with a Chance of Meatballs by Judi Barrett (via Open Library)

  • Reading a book such as Cloudy With a Chance of Meatballs by Judy Barrett. Discuss using questions such as:
    • "What are some ways that Chewandswallow is the same as where we live? How is it different?”
    • "What are some problems that we encounter because of our weather?” (e.g., snow can become frozen solid into ruts and make walking and driving dangerous; when snow and ice melt it can cause flooding)
    • "What were some good things that came out of the weather in Chewandswallow that we would not get with our weather?" (e.g., they used leftovers to feed the cats and dogs and animals in the oceans; they put it back into the Earth to make the soil richer for growing flowers)
    • "What are some problems Chewandswallow residents encountered because of the change in their weather?” (e.g. all of the solid foods were piling up and not being eaten or composted; the liquid syrup nearly flooded the town)

    Observation Walk Chart (image by Let’s Talk Science)

  • Questions and wonderings that arise from a neighbourhood walk to look for examples of everyday liquids and solids. Discuss using questions such as:
    • "What are some things you saw on our walk that you would classify as ‘solid’? How do you know that they are solid and not something else?” (e.g., a solid maintains its shape and cannot be poured)
    • "What are some things you saw that you would classify as ‘liquid? How do you know that they are liquid and not something else?” (e.g., a liquid takes the shape of the container it is in and can be poured)
    • "Are there some things that you were not sure of? Which would you predict they might be – liquid or solid? Why do you think that?”

    Cover of A Rock Can Be… by Laura Purdie Salas (cover image by Let’s Talk Science)


  • Reading books such as Water Can Be… and A Rock Can Be by Laura Purdie Salas. Discuss using questions such as:
    • "What are some characteristics of water that are illustrated in the book?” (e.g., water takes the form of the ‘container’ it is in; water can change from a solid to a liquid and back again)
    • "Why do you think water can be so many different things?”
    • "Look closely at the pictures. What hints do they give about how water turns into a solid and even into a gas/vapor?” (e.g., temperature change to below zero turns liquid water to ice; heat changes ice to liquid water and then to water vapor)
    • "When water changes, is it still a liquid? Why or why not?”
    • "What are some things that we learn about properties of solids from the book?” (e.g., solids can be used for a lot of things because they maintain their shape; not all solids are hard)
    • "Water changes when temperatures change. How do solids change?”
    • "When a solid changes, is it still a solid? Why or why not?” (e.g., when a candle melts it becomes a liquid; when a glass breaks into pieces, the pieces are still solid)

Materials and Preparation (Click to Open)

materials

Materials (Photo by Let's Talk Science

Materials:

  • paper plates, divided into sections, for exploring solids
  • small containers for exploring liquids and for mixing liquids and solids
  • a variety of common liquids such as water, milk, vinegar, honey, corn syrup, molasses, oil, liquid dish soap, hand/body lotion, soda water, etc.
    • Note: be aware of any student sensitivities to scents from dish soap, body lotion, etc.
  • a variety of common solids such as sugar, sugar cubes, icing sugar, flour, cornmeal, cornstarch, dry cereals, baking powder, baking soda, etc.
  • plastic or wooden sticks for mixing
  • measuring spoons
  • materials

    Materials (Photo by Let's Talk Science

  • a large bowl for exploring buoyancy
  • materials such as corks, coins, wood, small rocks or pebbles, a crayon, a plastic cube or building block, a spoon, etc.
  • hand lenses
  • newspapers and paper towels or cloths for cleaning up spills.

Preparation:

  • set up areas in the room where students can:
    • use their senses to explore various aspects of familiar solids and liquids. For example, students may wish to explore how different liquids move at different rates or examine household solids using a hand lens.
    • explore what happens when liquids are mixed with other liquids, solids with other solids, and a specific liquid with a variety of different solids.
    • compare the buoyancy of different liquids
  • pre-measure liquids and solids for mixing.
  • mark off sections on paper plates for exploring a variety of solids at one time.

What To Do

Students develop and apply the skills of observing, comparing & contrasting and predicting as they explore the properties of common liquids and solids.

Students:

  • Observe and compare and contrast a variety of common liquids using their senses
    • Educator reminds students not to put anything in their mouths unless told it is safe to do so.
    • Educator facilitates discussion about the liquids, encouraging use of descriptive words for how liquids feel, look, smell, and move.
    • Educator walks through the process of exploring the buoyancy of liquids by placing 125 ml of a liquid in a clear plastic container, then gently placing an object on top of the liquid and asking students to observe what happens.
  • Compare and contrast the buoyancy of solid objects in a variety of common liquids
    • Educator facilitates observations and discussion about the buoyancy of the liquids tested, encouraging the use of comparative words to describe what was observed.
  • Predict what will happen when two liquids are mixed together
  • Check predictions and describe and record observations about changes in the characteristics of the liquids.
    • Educator facilitates discussion about ways in which students can keep track of which liquids were mixed together and what was observed
  • Explore, compare and contrast a variety of common solids using their senses.
    • Educator facilitates discussion about the solids, encouraging use of descriptive words for how they feel, smell, and how they look when observed with and without the use of a hand lens.
  • Predict what will happen when two solids are mixed together
  • Check predictions and describe and record observations about changes in the characteristics of the solids.
    • Educator facilitates discussion about ways in which students can keep track of which solids were mixed together and what was observed.
  • Predict what will happen when a liquid and a solid are mixed together
  • Check predictions and describe and record observations about changes in the characteristics of the liquids and/or the solids
    • Educator facilitates discussion about ways in which students can keep track of which solid was mixed with which liquid and what was observed.
  • Discuss what was learned and describe some ways in which solids and liquids can be combined to make useful substances (e.g., flour and water make paste; milk and chocolate powder make chocolate milk)

Assessment

Observe and document, using anecdotal comments, photos and/or video recordings, students’ ability to:

  • Observe – students observe changes in characteristics of liquids and solids when they are mixed together (e.g., when various liquids are mixed with each other, when various solids are mixed with each other and when certain liquids and solids are mixed with each other)
  • Compare & Contrast – students use their senses to compare and contrast characteristics of various liquids and solids (e.g., view salt with and without a hand lens and observe how it changes when it is mixed with a variety of liquids)
  • Predict – students predict what will happen when various liquids and solids are mixed together (e.g., predict what will happen to dry cereal when it is mixed with liquids such as water and honey)

Co-constructing Learning

Students:
Saying, Doing, Representing

Educator Interactions:
Responding, Challenging

Students use their senses to explore, compare and contrast a variety of common liquids.

  • “What are some words you would use to describe how the liquids look?”
  • “How would you compare the way objects look when you view them through each of these liquids?”
  • “How would you compare how each of the liquids feel when you rub them between your fingers?”
  • “Which of the liquids have a scent or a smell? How would you describe it?”
  • “What did you notice about how each of the liquids moved? What words would you use to compare what you observed?” (Viscosity is a way to describe a liquid’s movement against gravity/its thickness.)

Students explore, compare and contrast a variety of common solids using their senses.

  • “What are some words you would use to describe how the solids look? How would you compare what you saw with just your eyes to what you saw when you looked at the solids through a hand lens?”
  • “How would you describe how each of the solids feel when you rub them between your fingers?”
  • “Which of the solids have a scent or a smell? How would you describe it?”

Compare and contrast the buoyancy of solid objects in a variety of common liquids

  • “What did you predict would happen to the xx when you placed it in the xx? What made you think that? Was your prediction accurate?”
  • “What did you predict would happen to the xx when you placed it in each of the other liquids? What made you think that? Was your prediction accurate?”
  • “How did the information you gathered about the liquids using your senses help you to predict whether the stone would float or sink?”

Students predict what will happen when various liquids are mixed together, check their predictions and describe and record observations about changes in the characteristics of the liquids.

  • “What did you predict would happen when you mixed x and y together? Why did you think that would happen?”
  • “What did you observe about the viscosity of x and y before you mixed them together? What did you notice about the viscosity of the liquid you got when you mixed x and y together? Why do you think that happened?”
  • “Did any other characteristic of the liquids (e.g., can be poured, takes the shape of its container) change after you mixed two together? Why do you think this happened?”

Students predict what will happen when various solids are mixed together, check their predictions and describe and record observations about changes in the characteristics of the solids.

  • “What did you predict would happen when you mixed x and y together? Why did you think that would happen?”
  • “What did you observe through the hand lens about x and y before you mixed them together? What did you notice about x and y after you mixed them together? Why do you think that happened?”
  • “Did any other characteristic of the solids (e.g., cannot be poured, maintains the shape) change after you mixed two together? Why do you think this happened?”

Students predict what will happen when various liquids and solids are mixed together, check their predictions and describe and record observations about changes in the characteristics of the liquids and/or solids.

  • “How will you record which liquids and solids you mix together, what changes you predict will happen when they are mixed together and what observations you make after they are mixed together?”
  • “How will you use what you have learned about liquids and solids to make your predictions about what changes you expect to see when you mix the liquids and solids?”
  • “Which mixture produced the most noticeable change in the solid? Which mixture produced the most noticeable change in the liquid?”

Cross-Curricular Connections

Literacy

  • Extend understanding of oral texts by connecting the ideas in them to their own knowledge and experience (e.g., after a discussion of results of their exploration of mixing of solids and liquids, students describe examples of experiences they have had such as making a salad dressing with oil, vinegar and herbs, mixing yeast with other solids and liquids to make bread, etc.)

Mathematical Thinking

  • Measure using standard and non-standard units (e.g., measure the amount of liquids and solids used when exploring changes in their characteristics)

Extending the Learning

If your students are interested in learning more, the following may provoke their curiosity:

  • Students may wish to explore how changes in solids and liquids impact them, their families, the community and the environment. For example, they could consider weather-related situations such as when rain turns to sleet or freezing rain.

  • Exploring Ooblek (photo by Let’s Talk Science)

  • Prepare a batch of ooblek. Provide opportunities for students to explore the ooblek. Discuss using questions such as:
    • “Is ooble tok a solid or a liquid? Why do you think that?”
    • “When we want to change a solid a liquid, what do we do? (e.g., we might apply heat.) When we want to change a liquid to a solid what do we do?" (We take the heat away.)
    • “What do you predict might happen if you squeeze the ooblek very tightly? Why do you think that?”
    • “What do you predict will happen when you loosen the pressure on the ooblek? What makes you think that?”
    • “How did the ooblek surprise us?” (Ooblek requires pressure to change from a solid to liquid.)
    • “What do you predict might happen if we froze the ooblek? How can we find out? What do you predict the ooblek will be like when it thaws – will it feel the same, and behave
      corrosive substance warning label

      Corrosive substance warning (photo by Let’s Talk Science)

      the same? Or will it feel and behave differently? How can we test our predictions?”

  • Some liquids and solids used in our homes, garages and workshops in labs may be hazardous unless we take the proper safety measures when using them. Organizations have developed a series of pictograms (e.g., WHMIS or Workplace Hazardous Materials Information System) that help to identify the hazards of products that are being used. These pictograms represent the potential hazard of a product (e.g., fire, corrosive, health hazard). While these symbols may be presented in different ways e.g., inside a red triangle, a red diamond or a yellow triangle), the symbol remains the same.
    Students may wish to explore the meaning of these international symbols
    fire warning label

    Fire warning and Poison warning (photo by Let’s Talk Science)

    that give us information on the safety of substances. Educators may wish to bring in empty containers bearing these symbols and discuss with students what they think the symbols might mean and why they are placed on these products. Care should be taken to assure students that the symbols help us know how to safely use and dispose of the products so there is no harm to us or to the environment.