Solid, Liquid, or Gas???

So many experiments, so much fun learning! This section forms the basis for grade 6 learning in flight and electricity!

Activity and Resource Ideas:

• One of the best resources we have found is the Perimeter Institute of Theoretical Physics Unit for Grade 5 on States of Matter. This inquiry unit has excellent math concepts and reviews states of matter, physical changes, and 3D printing! Very fun! We selected sections to use when reviewing states of matter for our Grade 6's before learning about concepts in flight and electricity. (link found in the Resources page). In this unit, we started by doing the first activity in this resource, which involves sorting common items into their own categories in groups, discussing commonalities between items, and eventually coming up with a class definition of a solid, liquid, and gas - noting that some things don't seem to fit into just one category! This leads into making 'oobleck' and 'slime' - see below!
• We like to show some Bill Nye the Science Guy older videos at this point to show various other experiments and fun demonstrations. Some of the applicable videos are 'Atoms and Molecules', 'Chemical Reactions', 'Phases of Matter', and 'Fluids'. Plus they are super engaging and fun for kids to watch!

Activity 1: OOBLECK

• After discussing and completing the sorting activity in the Perimeter Institute Unit for Grade 5 States of Matter and coming up with our definitions of solid, liquid, and gas, we put our definitions to the test by making some Oobleck - or Magic Mud. Here is a link to an explanation of what it is and why it fits the definition of a non-Newtonian fluid (not a solid, liquid, or gas!) www.futurity.org/oobleck-cornstarch-1057042-2/

Materials:

• corn starch
• water
• small containers - I use cleaned apple sauce containers or baby food jars or petri dishes
• spoons - just metal or plastic
• food colouring (optional)

Safety Notes: This activity is safe to touch but it can be messy so students should be careful not to get the oobleck on their clothes as it may stain.

Lesson Plan:

1. Set the Stage: Activate Prior Knowledge by asking students questions like:

• So now that we know what solids, liquids, and gases are usually like, we are going to make a cool substance that defies the usual explanation! Have you ever heard of oobleck or magic mud? (answers will vary)
• Does anyone know what oobleck or magic mud is made of?
• What state of matter is corn starch? Hold it up. (solid) What state of matter is water? (liquid at room temperature)

2. Prepare for and conduct the experiment:

• Notes:
  • The usual rule of thumb for this experiment is a 2 to 1 or (1 1/2) ratio of cornstarch to water - so I first discuss the ratio (to bring some math into our science time!)
  • I set up a couple of water stations where students can go and get spoonfuls of water, and a couple of corn starch stations where students can go and get their corn starch. Half of the fun is letting students do this on their own so they can do the measuring and the stirring!
• Doing the experiment:

1. Discuss the ratio of 2 to 1 (or a bit more than one) of corn starch to water. Discuss how to measure this using the spoons (I am intentionally vague on this so that we can see how accurate measurements are important later).

2. Have students go to the corn starch station with their spoon and their container. I usually tell them to do 2 spoons of cornstarch.

3. Then students go to the water station and add the 1 to 1/2 spoonfuls of water to the cornstarch.

4. They need to stir (and add food colouring at this stage if they want to or you want them to - 1 drop is lots).

5. Let them examine their own oobleck. Some will find they have added too much cornstarch and ask if they can add more water - some will find theirs to be too runny and want more cornstarch. I usually tell them that they can't add anymore at this point until we examine what is happening!

6. Have them share what their oobleck looks like with the class - some will be runny, some will be harder, some will be just right.

• Ask - Why do you think the ooblecks didn't turn out the same? (you are looking for them to figure out that it is because of experimental error based on the amounts used - some students will use a heaping spoonful and some will use less so it is hard for them to turn out the same).
• Ask - How could we get the same consistency of oobleck every time? (use measuring spoons that are all the same and level them off so you are adding the same amount of water and cornstarch each time)
• Ask - what do you think oobleck is - a solid or a liquid? Have students vote! Have a discussion about how it can act like both depending on how much water is added. You can discuss what a non-Newtonian fluid is and discuss - see the link above from Futurity.

Activity 2: Make some Slime!

• To continue the fun, make some slime! See the Steve Spangler recipe and video explanation (link below) for a really good recipe! I emphasize using measuring cups during this experiment to see if all the 'slimes' come out the same!
• You will need:
  • 1 cup or 250 mL measuring cup
  • 1 tablespoon - 15 mL measuring spoon
  • enough measuring cups to do equal parts of water and glue for each pair of students - I would recommend using a 1/4 cup or 60 mL measuring cup for each pair
  • spoons for stirring
  • containers for making it - I usually use some small bowls, beakers, or 2 cup (500 mL) measuring cups - 1 for each group
  • food colouring
  • Follow the recipe on the link - https://www.stevespanglerscience.com/lab/experiments/glue-borax-gak/

Discussion:

• I use this experiment to discuss a few important science and math ideas:
  • Precise measurements and why it is important to use measuring tools to help us measure solids and liquids carefully when making new substances (ask the students why it is important to use measuring cups and spoons when baking!)
  • Chemical reactions - discuss what is happening with the borax and the glue solution. Can you separate the borax from the glue after you make slime? (No) Why not? (they have combined chemically to make a new substance, just like you can't take the ingredients out of a cake once they have been mixed and baked together)
  • Is it a solid or a liquid or a non-Newtonian fluid? Have a vote!
  • Use this to examine fluids - thick versus thin - and introduce the term 'viscosity' - which they will see later in the Viscosity experiments.
  • If your students want to make another non-Newtonian fluid, they can try making quicksand - see the link for details: http://www.sciencekids.co.nz/experiments/quicksand.html

Overall Assessment for Math Expectations:

• Math - estimate, measure, and record quantities, using the metric measurement system; make connections among mathematical concepts and procedures, and relate mathematical ideas to situations drawn from other contexts; develop, select, and apply problem-solving strategies as they pose and solve problems and conduct investigations, to help deepen their mathematical understanding; develop and apply reasoning skills to make and investigate conjectures and construct and defend arguments; communicate mathematical thinking orally, visually, and in writing, using everyday language