Life in Lockdown – Decorate our streets!

Making homemade chalk is easy a great way to connect as a family!

Life in New Zealand has changed rapidly. Our borders are closed, domestic travel restricted, our schools and shops closed, and we are asked to remain at home in order to restrict the spread of Covid-19. Cars are now to be used only for essential travel (the doctor, pharmacy, or supermarket) and people may only leave their house to walk nearby. Social distancing is everything.

Our big field trip for today was walking to the top of the driveway and drawing pictures that the kids in the houses nearby can see from their windows. Creating chalk, with a few simple ingredients from the supermarket, has been both art and science. It’s also a way to share a little love and kindness with the community around us.

Why not bring a little colour to yours?

Life in lockdown: Share some love and decorate our streets!

How to make home made chalk

Ingredients

  • Cornflour
  • Water
  • Food colouring
  • Cardboard tubes
  • Waxed paper / baking paper
  • Scissors
  • Sellotape or rubber bands

Note: Alternative ingredients include plaster of paris + tempera paint, or a 1:2 ratio of very finely crushed eggshell + flour.

Directions

  1. Prepare your moulds. Toilet paper rolls are a good size; I find a bread knife does a good job of sawing longer cardboard inner tubes into parts.
  2. Cover the bottom of your cardboard tubes with waxed paper and tape / elastic band into place. You then want to roll more waxed paper and slot it inside (you may need to trim to size).
  3. Pour cornstarch into a bowl and then add food colouring of your choice. Slowly add water and mix well. You want to add just enough water to create a very thick [viscous] mixture.
  4. Pour or spoon the mix into your moulds.
  5. Pop into a hot water cupboard (or somewhere warm to dry). You want as much of the water to evaporate as possible to dry before use (about 24-48 hrs).
  6. You can then removed from the moulds and let the kids have fun!

Tip

If you add too much water then it will have difficulty drying (and remaining contained within the moulds). Never fear! Treat it as a chemistry and physics lesson all-in-one for the kids. You have just created a non-Newtonian fluid 🙂 You can take your ooblek outside for messy play fun with the kids. Pour it into your hands and watch how it becomes a solid if you clench your fist but magically liquefies if you release the pressure!

Home Science: Make a colour changing magic potion!

These colour changing molecules can be changed from indigo to brilliant blue or bright pink with a few simple experiments!

Pigments are molecules that contain colour and the ones in red cabbage juice ( anthocyanin ) are pretty special. By adding a base or acid, we can both change their shape and their colour! The pigments are easy to collect and the basis for two easy home experiments: Colour Changing Magic Potions and Making Litmus Paper.

First, you will need to collect some magic molecules from a red cabbage: click here to find out how.

Materials

Change your purple cabbage juice to blue by adding a base and to red/pink by adding an acid.

Directions

  1. Pour your prepared red cabbage juice into two clear glasses or small bowls.
  2. Into one glass, stir 1 tsp of baking soda. Watch the solution turn blue – indicating that the pH has turned basic.
  3. Into the second glass, stir 3 Tbsp of white vinegar. Watch the solution turn red/pink – indicating that the pH has turned acidic.
  4. For fun, pour the glass containing vinegar into the glass containing baking soda and watch them foam! Tip: for less mess, pour both solutions into a big bowl!
Foaming magic potion fun!

Home Science: Making Litmus Paper

Make your litmus paper to test acids and bases – it’s easy!

You don’t need expensive chemistry kits containing dangerous chemicals to have fun doing science at home. This simple (and colourful) experiment will help you make you own litmus paper so that you can test acids and bases using simple household ingredients. You can also test these by making a colour changing magic potion!

First, you will need to collect some magic molecules from a red cabbage: click here to find out how.

Materials

  • Red cabbage juice
  • Paper towels
  • Water
  • Dishwashing Liquid
  • Lemon juice
  • Baking Soda
  • Baking Powder
  • Vinegar
Making home made litmus paper
Home-made Litmus Paper

Directions – Part 1

  1. You will need your red cabbage juice (cooled and strained) and some paper towels. I folded mine twice to make thick squares.
  2. Quickly dip / submerge the paper towels into the red cabbage juice. Don’t hold them under for too long as you want them to collect the colour pigments but not get so soggy that they fall apart. It’s a little like candle dipping – you may need to do a couple of dips to get a good colour.
  3. Place the purple paper towels on a clean tray (that won’t stain) and put them somewhere warm (like the hot water cupboard) to dry until the next day.
  4. You now have litmus paper! Cut them into strips for easy dipping.
Testing Acids and Bases

Directions – Part 2

  1. Using glasses or small bowls prepare the solutions that you want to test. Your litmus paper will stay purple in ph neutral solutions, turn red-pink in acidic solutions, and turn blue in basic solutions.
  2. Dip away!

We used:

Bases: soapy water, baking soda, baking powder.

Acids: vinegar, lemon juice.

Don’t worry if your experiment doesn’t go perfectly (ours didn’t!); simply use it as a talking point to discuss why things didn’t turn out as expected. In our case, the detergent and baking powder didn’t dissolve properly which meant that out litmus paper stayed purple (recognising the ph neutral water). For more ideas on common acids and bases: click here.

Home Science: Making Magic Molecules

These colour changing molecules can be changed from indigo to brilliant blue or bright pink with a few simple experiments!

Pigments are molecules that contain colour and the ones in red cabbage juice ( anthocyanin ) are pretty special. By adding a base or acid, we can both change their shape and their colour! The pigments are easy to collect and the basis for two easy home experiments: Colour Changing Magic Potions and Making Litmus Paper.

Materials

  • 1/2 red cabbage
  • Hot water
  • A food processor (or a big pot)
  • Bowl
  • Fine colander or flour sieve
Simply blending the red cabbage in boiling water produces amazing bubbles!

Directions

  1. Shred or coarsely chop the red cabbage.
  2. You can then choose whether to boil or blend. I chose blending and it’s meant to result in slightly better colour.
    • Boil: Pop in a pot with enough water to cover the cabbage and boil for 15 minutes.
    • Blend: Pop in a food processor with about 3 cups of boiling / hot water. Blend until the cabbage is finely processed and then leave to soak for 15 minutes.
  3. Allow the cabbage mixture to cool and then strain the juice into a bowl. Tip: The juice will stain so glass is great if you have it. I used a flour sieve to strain mine into a glass pyrex jug.

You now have the cabbage juice you need for your two science experiments!

Added Extras

You can also freeze leftover juice in ice cube trays to make all natural coloured icing for birthday cakes or cupcakes!

Caramel Crunch Cookies

Caramel Crunch Cookies

These delicious crunchy cookies are also a great opportunity to discuss science in the kitchen! STEM discussion points follow after the recipe 🙂

Ingredients

  • 125 butter
  • 1/2 brown sugar
  • 1 Tbsp maple syrup or golden syrup
  • 1 Tbsp milk
  • 1 1/2 cups plain flour
  • 1 tsp baking soda

Allergies: soy free, egg free, nut free.

Directions

  1. Start the oven preheating to 180’C / 350’F.
  2. Have a grown up mix the butter, sugar, maple syrup, and milk in a pot. Heat until the butter is melted and the mixture is almost boiling – you’ll be able to see the surface tension change as it begins to think about bubbling. Make sure that you stir constantly so that it doesn’t stick or burn.
  3. Remove from heat and allow the caramel to cool to lukewarm.
  4. Sift the flour and baking soda into the pot and mix into the caramel.
  5. Stir well and it will turn into a caramel coloured cookie dough.
  6. Roll the cookie dough into balls and flatten on a baking tray (either greased or lined with baking paper).
  7. Bake for 10-15 mins or until golden brown.

Science in the Kitchen (STEM)

  1. Gravity & Weight: When you’re using kitchen scales to measure out the butter, take a few moments to talk about why things have weight and why we weigh them. That butter would weigh about 20g on the Moon and about 315g on Jupiter.
  2. Solids, Liquids, Gas: It’s a good idea to have a grown up do the stirring with the caramel mixture as it gets very hot; keep young helpers interested by helping them to safely view the way the ingredients change. Ask them if the butter and sugar going into the pot are liquids or solids (the latter); then show them what happens when heat is applied (becomes liquid); as the mixture cools and is combined with the flour it’s state changes again (solid).
  3. Gassy Bubbles: Ask young helpers what’s different about the ingredients in this recipe. The answer is that it uses baking soda rather than baking soda. The baking soda causes small carbon dioxide gas bubbles in the cookie mix causing it to rise when it goes into the hot oven. Tip: Get the cookies in the oven quickly as the longer the mix is left at room temperature, the less the cookies will rise.
  4. Sweet Surprise: A great way to see baking soda in action is to make a candy version of these cookies. Have a go at making Hokey Pokey!