Science!

Session 1

Brainstorm - Mad Scientist pantry

From our drawings of pantries

• Organise things onto separate shelves so you don’t get the wrong thing and it is easy to find
• Label the jars
• Keep food separate to chemicals
• Acids (it can burn) are kept in glass in a very safe place. Kept out of reach of children.
• Separate storage for animals for experiments
• Different areas for different things - plants, animals, chemicals
• Safety gear in pantry
• Powders - for mixing
• Liquids - for mixing
• Test tubes, jars, test tube holders, mixing spoons
  
  
  
  
  
  

  Session 2:

  
  

  How items are grouped in our pantries...

  
  

  • Foods are in different areas
  • Everything has its place.
  • Metal containers grouped together (cans)
  • Baking ingredients (flour, cocoa powder, baking powder, etc) are grouped together.
  • Liquids are grouped together.
  • Seasonings together so they are easy to find
  • First Aide stored low so that it can be easily reached
  • Sweet, yummy things are stored high in the pantry so they can’t be got at easily.
  • Spreads are together so they easy to access
  • All perishable food is kept in a cool place in the middle of the pantry.
  • Gadgets like the toaster, coffee machine, blender, food processor are kept on the bench because they are used all the time.
  • Bench for a work area.
  • Some things (potatoes) are kept in a drawer where it is dark and it keeps them cool and fresh.
  • Mixing bowls, etc are kept in a different place.
    
    
    
    
    
    

    Our wonderings about a Scientist’s pantry...

    We are wondering if:

    • you walk into the pantry?
    • there is a big bench in the middle of the pantry for working at?
    • the pantry is computerised?
    • the pantry is like a laboratory like in the movies?
    • there is a code to get in if there are secret experiments?
    • the pantry is organised using a code (colour/number)?
    • the windows are covered?

    
    
    

    Session 3 - Hard or Soft

    • Some were unsure about handling the mixture and were then surprised at the texture of the mix.

    As it dried it turned back into powder, and as it was cornflour, felt funny on their hands.

    • Led to a discussion about molecules and atoms. Watched some You-Tube clips.

    
    

    Session 4 - Brain Sludge

    • Went well - Emma said it was like it parted in her hand, Jack said it must be the vinegar and did another experiment using water to prove vinegar was the thing that changed the milk. Zoe said that vinegar is an acid. Watched YouTube clip about acids and bases. Want to know more about acids and what they can do.
      
      
      
      

      Session 5- Growing Glop

      
      
      

      • The longer we left the glop, the more it rose. Students used all their senses to evaluate the experiment.

      
      

      Session 7 - Making Changes

      
      
      

      • Good discussion and use of evidence to back up ideas. Connections made to home baking. Led to some students doing some experiments at home with milo (heating the granules up, baking in the oven) to see if the state could/would change.

      Session 5- Making Mixtures

      
      

      • Sand & water - the water was still in the sand, we knew this because when we squeezed the wet sand, water dripped out. To make the sand dry again, the water to evaporate

      • Butter & Sugar - the sugar dissolved into the butter when we mixed it. The butter heated up when we beat it and the sugar was merged into the butter. We don’t think it can be separated because the sugar has dissolved into the butter.

      • Two different colours of Jelly - the jelly crystals dissolved in the warm water and made an orange colour. We can’t turn them back into jelly crystals because they have dissolved.

      
      

      • Salt & Sugar - they combined and we couldn’t tell the difference unless we tasted it. We are not sure how you would separate them. Sugar has bigger grains?
        
        
        Session 9 - Melting
        

        How can we melt an ice-block?

        
        

        Applying heat

        
        

        • by leaving it in the sun
        • from your hand, we are warm blooded
        • using an element
        • using a microwave
        • by licking or sucking it
        • by putting it under running water
        • wrapping it in something

        The iceblock melted when we applied heat. There was a little bit of steam so if we froze the liquid into an iceblock again it wouldn’t be the same size as it was originally was.

        
        

        How can we melt sand?

        • we can’t melt sand because it is rock
        • we need a high temperature to melt sand

        
        

        How can we melt butter?

        • apply heat

        
        

        How can we melt sugar?

        • apply heat
          
          
        
        
        
        

        Any substance that holds its shape at room temperature is a solid. Liquids take the shape of whatever container they are in even if it is open on the top, gases will not stay in any open container. Any substance can be any of these three physical forms depending on the temperature.

        
        
        

        • Much enthusiasm and discussion around what was happening. Obviously didn’t get the sand to turn into glass but it was Luke Comer who said you need a really high temperature to melt the sand. Lots of discussion around the 3rd column in the table above - can we turn it back into a solid? We had to look at the definition of ‘solid’ to see if what happened to the sugar was indeed a solid again but in a different state to how it started out as.

      
      

      
      
    
    

    Mixing Salt and Water

    
    

    Boiling the water to get the salt back.

    
    
    

    Added salt to cold water then heated it up til it was boiling. The water evaporated into steam and left salt behind. It felt like a powder compared to the original salt grains. They were powdery flakes and felt softer. Powdery salt tasted stronger.

    
    

    
    

    • lot of discussion around where the water was going (steam), making connections to cooking at home (eggs) and what would be left in the bottom of the pot.
    • Observed that the salt was still in the water (that it had dissolved). Many guessed that the water was being evaporated by applying heat and the steam coming off the pot was the water.
    • As the pot sides turned white they realised that it was more than likely the salt coming back.
    • Many were surprised at how soft and fluffy the salt was and how it had a more intense flavour.

    
    
    

    WHY "DISSOLVING" IS A DIFFICULT IDEA

    
    

    These notes help explain why dissolving is not a straightforward concept for students to grasp. Researchers warn that this concept is much harder than teachers may realise. Even 16-17 year olds may try to describe the unseen events of dissolving based on their understanding of changes they can observe.

    
    
    

    Misconception 1: Dissolving is confused with "melting"The Learning in Science Project (LISP) reported that 25% of the students interviewed used the terms melt and dissolve as if they were synonyms. Two reasons students might think like this are:

    • In both melting and dissolving a solid appears to turn into a liquid;
    • The use of hot water speeds up dissolving, just as heat speeds up melting.

    Misconception 2: The solid ceases to exist when it dissolves Students' reasoning may be along the lines:

    Sugar + Water = Water (without sugar)

    
    

    Students who state this are relying on what they see, and may not yet understand that:

    • Even though you cannot see the solid it is still present;
    • Solids break up into very tiny (but still essentially solid) particles as they dissolve. These particles are so tiny they are no longer visible to our eyes.

    
    

    Misconception 3: Physical change and chemical reactions are confused.

    
    

    Some students may not realise that when a solid dissolves each molecule of the solid remains unchanged. It does not combine with the water to make a new substance, as in a chemical reaction.

     

      

    Misconception 4: Dissolving is thought of as storing away in small spacesSome students think that dissolved particles move into little "pockets" in the water where air bubbles have previously been.

    This may relate to the appearance of air bubbles as water gets warmer. Gases can dissolve in water too – but less gas particles can stay dissolved as water gets warmer. That's why the air comes out, not because it is replaced by a solute.  

     

    References:Ebenezer, J., & Ericson, G. (1996). Chemistry Students' conceptions of Solubility: A Phenomenography. Science Education, 80,(2), 181-201.

    Osborne, R., & Freyberg, P. (1985). Learning in Science: The implications of children's science. Auckland: Heinemann.

    
    

    
    

    Session 11-Acid or Base?

    
    

    
    

    
    

    Feedback:

    
    

    Using video and doing have helped us learn about acids and bases.

    
    

    Discussion around bleach and what it was - it is a base.

    Experimented with new chemicals and seeing the reactions - all the different colours.

    Colour range was red - pink  (acids) to blues, greens and yellow (Bases)

    Our tray was like a rainbow.

    Interesting to learn about the chemicals that are in our houses.

    There were lots of different colours and it was interesting watching the colours change, especially if we added more indicator.

    As time went on the dishwashing powder went from green to a yellow.