Fun With Acids and Bases – How to Use Red Cabbage as an Indicator

Red cabbage acid base indicato original

Do kids want to learn about acids and bases? If they’re like my kids then probably yes in theory – but in practice, “Not right now, thanks Mummy, I’m just finishing this game on Grid Club/making this cardboard helmet/playing my guitar”.

Do kids want to play with colourful potions? Absolutely! And once you’ve ignited their curiosity, of course they’ll want to know all about it!

Bring on the red cabbage and those old faithfuls, vinegar and bicarbonate of soda…

What You Need

  • Red cabbage (we used half a head)
  • Water (the book says to used distilled water, but we used tap)
  • Saucepan
  • Stove Top / Hot Plate
  • Glass jars/glasses etc (to pour the cabbage water into)
  • Household substances to test eg vinegar, lemon juice, bicarbonate of soda, soap
  • Marker pen or dry wipe marker (optional) to label the jars
red cabbage acid base indicator homeschool science

What You Do

  1. Roughly chop the cabbage and boil it in water for about 10 minutes.
  2. Drain (and discard/eat) the cabbage, reserving the water.
  3. Pour the water into as many jars/glasses as you have substances to test, plus one as a control.
  4. Add one substance (e.g. lemon juice) to each jar of purple cabbage water. Label the jar so you don’t forget what you’ve added.
  5. Observe any colour change, comparing against the control cabbage water (to which nothing has been added).

What Happened

The water the cabbage has been boiled in is dark purple.

C and J both chose to add vinegar  to their first jar, which turned the cabbage water a pinkish colour. Then they predicted (proper science!) what would happen when they added lemon juice, and were happy to confirm their hypothesis that lemon juice also turned the water pink.

The effect of adding bicarbonate of soda was more subtle.  We had to scoop up a small amount of the liquid with a teaspoon to fully appreciate the change – the water took on a blueish hue.

Red Cabbage Acid/Base Homeschool Fun

Soap turned the water very slightly blue, and soy sauce had no noticeable effect.

What We Might Do Next Time

What we forgot to try (there’s always something!) is adding vinegar or lemon juice to our bicarbonate of soda water.  If you get the quantities right, this should turn the water back to the original (purple cabbage) water colour.

There are also lots of other substances we might test – orange juice, milk, Coca-Cola, tomato sauce…

How Does It Work?

Science Experiments Book

I’ll hand you over to the Science Experiments book here:

“An acid is a substance that produces positively charged particles made of oxygen and hydrogen, called hydronium ions, when dissolved in water…

A base is the chemical opposite of an acid.  Bases produce negatively charged particles in water, called hydroxyl ions….

Cabbage water [is an indicator, which means it shows] whether a liquid is acidic or basic. [It changes] colour because the structure of [its] molecules changes depending on the amount of hydronium or hydroxyl present.”

red cabbage acid base indicator homeschool science

Taking It One Step Further

For this you’ll need a pack of pH-testing litmus paper (£2.76 on Amazon).

red cabbage acid base homeschool science

I gave the children a book of litmus paper and they dipped a fresh piece in each of their cabbage water jars. They compared the colour the paper turned with the colour scale on the book, to obtain a pH value.

Red cabbage acid base indicator homeschool science

I explained that pH is a measure of the acidity or alkalinity of a solution. (Bases that dissolve in water are called alkalis.) Acids have low pH’s, alkalis have higher pH’s.

red cabbage and litmus acid base indicator - homeschool science

C noticed by testing with litmus paper that our soy sauce solution was very slightly acidic.

Has anyone else tried this? Do leave a comment to let me know how it went or if you know of any other fun experiements with acids and bases!

More Hands-On Science Posts

How to Make Slime and Plastic

Fizzy Fountains

Copper-Plating a Nail

Thanks to Adventures In Mommydom for hosting Science Sunday!

Science Sunday

How To Make Slime and Plastic

Home Made Slime - Homeschool Science
This week we made our own biodegradable plastic and had hands-on (literally!)  fun with sticky slime.

Slime

You have to feel this stuff to believe it.  The children had way more fun playing with it than they’d expected.  Best of all, it’s so easy – five minutes to make, a whole afternoon of fun!

Home Made Slime - Homeschool Science

What You Need

  • Cornflour (cornstarch)
  • Food colouring
  • Water
  • Cup, bowl, spoon

What You Do

  1. Put a cup of cornflour (cornstarch) into a bowl.
  2. Slowly add water, stirring all the time, until the mixture becomes a sticky paste (add up to about half a cup).
  3. Add food colouring and stir to blend.
  4. Have fun with your slime! Notice how it both flows like a liquid and sticks together like a solid.

The Science

Slime is a “non-Newtonian fluid” because it doesn’t conform to Sir Isaac Newton’s rules about how liquids behave. It’s made of polymers – long chains of simple molecules.  When the chains are stretched out the liquid flows, but if you apply pressure the chains stick together.

How to Make Slime Collage original

What We Might Do Differently Next Time

This really is so easy. The only thing we’d do differently would be to be less concerned about the exact amounts of cornflour and water. You can always add more of either (or both). Cornflour is our new favourite science ingredient!

Home-Made Plastic

What You Need

  • Starch (eg cornflour/cornstarch, potato flour)
  • Glycerine
  • Vinegar
  • Food colouring (optional)
  • Aluminium foil
  • Wooden spoon/spatula
  • Old saucepan

How to make plastic - homeschool science

What You Do

  1. Mix together 1 tbsp starch and 4 tbsp water in a saucepan.
  2. Add 1 tsp glycerine and 1 tsp vinegar.
  3. Stir until blended.
  4. Put the saucepan on a low heat, stirring constantly.
  5. Observe the mixture change from a cloudy liquid to a clear gel.
  6. When the mixture is completely transparent and starts to bubble*, use the wooden spoon to spread it out on a sheet of foil.
  7. Wait a day for your plastic to set.
How to make plastic - homeschool science

What Happened

Watching the mixture turn into a gel was very cool. *Ours never became completely transparent or visibly bubbled (we made three batches) but the plastic turned out fine. (For our purposes! We weren’t planning any industrial applications.)

how to make plastic - homeschool science

I forgot to do step 6 for our first batch   (I’m not great at reading instructions) so our red plastic came out in globules that would do nicely as fake jam!

Then we made green plastic in the same saucepan, without washing it, which resulted in a gross concoction that might be given away with the Beano (I’ll spare you the photo). I had to make some nice fresh-looking blue in a clean pan after that experience. (The kids were out playing in the snow by this point but – hey – I was having fun.)

What We Might Do Differently Next Time

  • We might make some uncoloured plastic, to see if it turns transparent in the way the book describes.
  • We might experiment with different quantities of glycerine, which changes the rigidity of the plastic.
  • I wouldn’t use an ancient non-stick saucepan – bits of the non-stick coating came off in our plastic. The pan came completely clean after a soak so I’d use a regular, uncoated sort. Perhaps it’s time to invest in a dedicated science pan. 🙂
homemade_plastic_original (1) 2

The Science

Like slime, plastics are made from polymers. Their chain-like structure makes them flexible enough to mould while soft, then strong when set.

What Does Each of the Ingredients Do?

Starch contains polymers. Vinegar makes the chains stronger, and glycerine makes them more flexible.

The Book

Both these experiments come from Science Experiments: Loads of Explosively Fun Experiments You Can Do. We’re very much enjoying our journey through the book. A few of the experiments call for materials that are tricky or expensive to source (dry ice, powdered alum) – we’ll skip those for now – but most are inexpensive household items. I love the way the materials and instructions are clearly laid out with plenty of pictures.

More Hands-On Science

Fizzy Fountains – Diet Coke Geysers and Home-Made Lava Lamps

Copper-Plating a Nail

Science Sunday

We’re linking up with AdventuresInMommydom’s Science Sunday – thanks Ticia for hosting!

Field Trip to Benjamin Franklin House

field trip to benjamin franklin house at navigating by joy homeschool blogWhenever I write about a field trip I  feel like I’m back in infants school writing in my “news” book on a Monday morning: “We went to a museum.  It was fun.” (Though back then apparently all I ever wrote as “news” was that we’d been to the rubbish dump.  Easily pleased we were, back then.) (I might get out my crayons to draw a picture to go with this post.)

So.  Last week we visited Benjamin Franklin House, and it was fun, as well as educational.

Where is Benjamin Franklin House?

benjamin franklin house at navigating by joy homeschool blogBenjamin Franklin lived at 36 Craven Street, London, for sixteen years on the eve of the American Revolution (between 1757 and 1775). Franklin first came to try and negotiate with the British, so the building was really the first US embassy.    The house was built in 1730 and is the world’s only remaining Franklin home.  It has been carefully architecturally preserved. So when we were told of the “air baths” Franklin would take – standing naked at tall windows of the very room we sat in – it was easy to imagine ourselves back in time and giggle as we wondered what the folk sitting in the house directly across the narrow street must have made of the sight!

Before our Visit

Our visit fit in perfectly with Cordie’s electricity project.  In preparation, she read aloud to us How Benjamin Franklin Stole the Lightening, a wonderful living book about Franklin’s life and inventions, including how he harnessed lightening in his famous kite experiment.

how ben franklin stole the lightening

Electricity in Action

At the house, we saw a demonstration of the kite experiment, as electricity (generated using a Tesla coil) jumped down a (miniature) kite string into an attached key. A model church next to the Tesla coil showed us how lightening is attracted to tall buildings, and how a metal lightening rod protects the building by grounding the lightening (while a plastic rod has no effect).  A great opportunity to experience the sight, sound and smell of electricity up close!

benjamin franklin house lightening rod experiment at navigating by joy homeschool blog

lightening experiment at benjamin franklin house - navigating by joy homeschool blog

A Trip Back in Time

The museum’s educational team enthusiastically engaged the children in a number of activities throughout the house.  There was even an actress playing the part of Franklin’s landlady’s daughter, Polly Hewson, to take us on a guided historical tour!

benjamin franlin house historical experience at navigating by joy homeschool blog

Polly’s husband ran an anatomy school from the house, so there were hands-on anatomy-related learning activities, including an exhibit of human bones recently found in the basement of the house.

anatomy activities at benjamin franklin house - navigating by joy homeschool blog

Planning Your Trip

The Benjamin Franklin House Historical Experience is open to the public from Wednesdays to Sundays (£7 for adults, children go free).  On Tuesdays the house offers pre-arranged educational visits (including to homeschool groups), taking in the Student Science Centre, at no charge.  Check the website for up-to-date information.

Project-Based Learning: Electricity and Magnetism

electricity project at navigating by joy homeschooling blog

Project-based homeschooling in our newly reorganised space has got off to a great start, with all three of us learning a lot! Today I’ll talk about what Cordie (8) has been doing in her project time.

Cordie’s Electricity and Magnetism Project

Cordie immediately knew she wanted to do her first project on electricity and magnetism. Over the summer she read a few books I’d strewed around (in response to her expressed interest) – including  The Magic School Bus and the Electric Field Trip, Thomas A Edison – Young inventor, and How Benjamin Franklin Stole the Lightening.  By September she was ready to get hands-on!

electricity_books_original at navigating by joy homeschool blog

Klutz Electricity and Magnetism Kit

Klutz Battery Science at navigating by joy homeschooling blogWhen we set up her new project desk the first thing Cordie did was decorate it with a picture of Ben Franklin. 🙂  Next she got out our Klutz Electricity and Magnetism kit (which she had last played with a year ago) and experimented with connecting the wires to make the light bulb glow and the buzzer sound.

klutz electricity and magnetism kit navigating by joy homeschool

Then she ran up to her bedroom and used the bulb and wires to illuminate her upstairs landing of her dolls’ house.

dolls house illuminations at navigating by joy homeschool blog

Spot the crimescene

She loved the effect of this, and talked about how she’d like to light up the whole house, but thought it would be inconvenient to have the lights on all the time.  I was very proud of myself for not leaping in with suggestions about switches! Instead I smiled, nodded interestedly, and made notes in my project journal. I’ve included a photo of the lit up house in the photo collage I put up on her pin board, to act as a visual reminder.

Snap Circuits

Primary-Plus2-box-200w at navigating by joy homeschool blogNext Cordie wanted to browse Amazon for electricity kits.  She found this one (which I was happy to invest in on the basis it goes right through to KS3 (the end of middle school)).

Electricty Kit at navigating by joy homeschooling blog

This was the perfect next step – having played with the Klutz kit she understood that circuit components contain metal wires that have to be connected, but the relative ease of being able to snap the the Primary Electricity kit parts together meant she could make more complex circuits without the fiddliness of ensuring the wires were properly connected.   Knowing that there are no loose connections prompts a young scientist to look for other explanations as to why a circuit isn’t working!

Cordie’s spent most of her project sessions since then methodically assembling the components of the kit, following instructions in the accompanying manual.  I’ve sat quietly beside her as she worked, lending a hand on request to snap together tricky parts or to read aloud from the manual while she does the assembling.

Collaboration

I learned from Project-Based Homeschooling that collaboration is an important part of project work, and this has happened naturally so far. It first happened at home as Jasper (7) watched Cordie put together circuits and asked if he could play with the kit too.  They spent hours over the following days putting together and discussing circuits.  (During those few days I had to bulk buy 2 Amp fuses, much to the consternation of the nice elderly gentleman in the local electrical shop, who looked at me with concern and asked  nervously, “Is it the same appliance that keeps on breaking?”)

electricity project at navigating by joy homeschooling blog

Mad Scientist in the background

Cordie also discovered that a friend at our home ed group is interested in circuits too, in particular robotics circuits, and they’ve agreed to take their kits along next time, to explore together.

How Project-Based Learning Feels

Obviously a lot of learning is happening during these project sessions, which lifts the heart of any homeschooling mum, but there’s so much more to it.  I’m absolutely loving observing Cordie’s natural learning process in a way that wasn’t possible when I thought my role was to actively direct the process.  A few times she’s said she’s worried I’m bored (sitting quietly, doing as she asks) and each time I’ve given her a genuine reassurance that I’m really enjoying just being there beside her.  I sense that she’s beginning to relax a little now and trust that this is the real deal, that I’m not about to pounce and take over her project, or wander off bored and do my own thing. And that trust and sense of ease is carrying over into the rest of our homeschooling life.

Jasper has been using his project-time quite differently, but with equally pleasing results. I’ll talk more about that next time.

A Day In The Life of a British Homeschooling Family

a day in the life of a british homeschooling family - navigating by joy

Like many homeschoolers, there is no “typical” day in our household.  Our week is loosely structured around external activities like sports classes and our weekly homeschool group, and there are certain subjects that I aim to cover in a week, but other than that,  I like the flexibility of a routine rather than a fixed schedule.

Having said that, here’s an example of a typical, non-typical day!

530am I get up.  I’m not normally this early!  But it’s such a beautiful morning already  I decide I’ll enjoy some quiet time to myself.

645am I go back to bed and meditate/play Words with Friends until 730. I love how my iPhone lets me have a permanent scrabble game going with my mum who lives in Wales!

830am We’re having poetry tea with friends later, so I bake some gluten free/sugar free cookies with the children.  J has been so much calmer since we reduced his dietary sugar, gluten and dairy five months ago (on the advice of a complementary health professional) .  Since most bought products are either sugar or gluten free, I find myself baking a lot.  I’m not an experienced cook, so the recipe substitutions I make can be a bit random, as can the end products. Luckily the children are very forgiving.

850am As we put the eggs away, J asks if we can make pancakes.  I promise him that if he gets on with his maths and English without any fuss, there’ll be time to make some before we set out for our friends’ house.

855am Incentivized by pancakes, J physically drags me into my office, where C and J do most of their individual schoolwork. He does copywork from “Fox In Socks” and we practice phonics and spelling using The Wand.  For today’s maths we look at negative numbers in Primary Grade Challenge Math.

915am  J makes pancake batter. He and C got very good at making pancakes shortly after we changed his diet – gluten and sugar free English pancakes, made with goats’ milk, work really well!

10am We arrive at our friends’ house.  C and J run off to play with the other children (aged 12, 10 and 9)  while I catch up with my friend.  Later we sit at a beautiful table and eat cookies, drink tea from fine cups and saucers, and take turns reading poems aloud. These are the friends who introduced us to the Brave Writer lifestyle, and I love sharing Poetry Tea with them; it’s such a pleasure hearing the poem each person has chosen.

I read “A Summer Morning” by Rachel Field, because even though it’s only May, temperatures have been in the 80’s today.  After the weather we’ve had in England recently, it definitely feels like summer!

1130am On the way home we stop off at the park to enjoy the sunshine.

12pm We make another stop, this time at the garden centre, to pick up some compost: it’s finally safe to put the tomato and pepper plants outside!

1230pm Lunch.  J learned how to make cheese and ham tortilla flatbreads at our homeschool centre yesterday; he decides to make them again today. It requires a brick, apparently.  C obligingly finds one in her den at the end of the garden.  J teaches C how to make his new dish.  I do the bit at the hob, involving flattening the tortilla between the griddle pan, a saucepan and a tea towel-wrapped house brick!

homeschool gardening - navigating by joy

1pm C waters her vegetable patch while I plant out the tomatoes. J bounces on the trampoline then retreats from the heat inside.

phantom tollbooth - navigating by joy homeschoolers145pm C and I go to my office for her English and maths. We continue our discussion of literal versus metaphorical meaning using The Arrow and our novel, The Phantom Tollbooth. We discuss what clichés are and pick out a few from a list I had printed out; then we start an exercise from The Arrow, creating a story taking metaphoric meanings literally. It’s about a king standing on the tip of an iceberg.  C enjoys this so much that when I suggest finishing, she begs to do a bit more! Always a good sign 🙂  We finish by reading aloud a chapter of The Phantom Tollbooth.

We use Primary Grade Math Challenge for maths and C answers the level 2 questions on negative numbers.

245 pm Science: we continue our space travel project. The children make edible space shuttles following directions in this NASA Educators’ Guide.

We watch a You Tube video of the shuttle taking off and look at a printables of the parts of the space shuttle and the sequence of take-off, orbit, and landing.  C and J then assemble their own shuttles using bread, carrot, celery and hummus.  I video them “narrating” their own take-off to landing sequences on my iPhone.  C leads the narration but J contributes a piece of information he remembered from our recent visit to the Kennedy Space Centre – something I hadn’t even realised he’d taken in at the time – I love it when that happens!

edible space shuttle - navigating by joy homeschoolers

J follows his space shuttle snack with a plum from the fruit bowl, and then asks me to point out to him the plum tree in our garden. We look at the hard, grape-sized plums on the tree and I tell J how I ate the sweetest, juiciest plum from it on the day we moved into our house on 31 July 2007.  He said he is going to keep an eye on the plums’ progress. Sometimes I wish I made more time for formal nature study in our homeschool; then I realise that thanks to the huge amount of free time they have to spend outdoors, C and J are actually quite in tune with nature and the seasons.

boudicca - navigating by joy homeschoolers4pm History: I decide to squeeze in a bit of The Story of the World before swimming classes. J groans (he never likes the idea of history) but he soon joins C pleading for more when I stop after half a chapter on the Celts.  Half a chapter is all the Celts get in The Story of the World, but as they are our bit of ancient history, we’re spending a bit longer on them than our curriculum suggests. I read from our living book on Boudicca while C spontaneiously makes a Boudicca “doll” from a feather the cats brought it.

5pm C and J go to their swimming classes while I squeeze in half an hour in the gym. When the children were at school, exercising often felt like a chore.  Now I cherish my gym time!  We eat dinner at the sports centre cafe, and C and J have some time jumping around in the soft play area.

7pm We go straight from the sports centre to take C to Cub Scouts (where she is one of only two girls). Normally this signals the end of my day’s “work”, but Big J’s commuter train is delayed tonight so J and I go back out to collect C from cubs at 830.

930pm I’m relaxing with an alcohol free beer and watching The Vampire Diaries.

A good day!

Science And Eggs

When I tell people we homeschool, people sometimes ask about how I plan to do science as the children get older.  For some reason it’s the one subject they can’t imagine happening at home.

Well, my experience so far is there is a wealth of resources out there – books of fun experiments, great websites, inspiring blog memes like Science Sunday, plus of course the usual wonderful selection of homeschool blog posts.  In fact science is possibly the easiest subject to find ideas for. All these, together with a few living books and the children’s innate curiosity, would almost certainly be enough to give primary aged children a great start in science.

Not the most interesting photo ever. But the tablecloth is nice.

Then when I read Weird, Unsocialized Homeschoolers’ review of the REAL Science Odyssey curriculum, it sounded brilliantly hands-on, plus it ticked the box of being available as a (UK-friendly) downloadable eBook, so I thought we’d give it a go.

We began the “Life” curriculum (C’s choice) before the summer break so we started this year’s science with a recap of the differences between living and non-living things.  In keeping with his new love of writing (really!) J eagerly seized and completed the chart I had half filled out back then on his behalf (him dictating what to write).  His answers to whether a rock or a bicycle moved on their own, breathed, reproduced etc were rather random but very interesting and the exercise definitely got him thinking!

Next we talked about how living things are made up of tiny cells, and looked at an egg as a rare example of a cell that’s big enough to see with our eyes.   Luckily I had half a dozen slightly-out-of-date eggs to hand because it took the children a few goes to crack their eggs without breaking the yolk!

Before we cracked the eggs we looked at them through magnifying glasses and noted the tiny holes in the shell through which air and water pass.  Then we talked about the parts of the egg and their purpose, and found the tiny white blastodisc  in the yolk and the tail-like chalaza which anchors the cell, neither of which I have ever noticed before!  We’d lost J to lego by the time it came to drawing the egg, but C enjoyed colouring and labelling hers, and I left J’s page blank – who knows when he might decide to come back to it with a wave of enthusiasm!

I don’t know how science will evolve for us if  we’re still homeschooling at senior school level – I’ve heard of people getting together in science co-ops and even using school lab facilities – but thinking back on my own school science experience, I don’t have the slightest doubt that if C and/or J are still at home, the freedom they will have to pursue their own interests at their own pace and on their own terms will definitely outweigh any shortcomings in facilities.  Besides, there’s not much you can’t get on the internet these days!

Marshmallow Geometry

In my usual take-myself-by-surprise fashion we found ourselves constructing 3D geometric shapes this morning over breakfast.  I had got in the supplies – cocktail sticks and mini-marshmallows – a few weeks ago, and had been storing the marshmallows in a tupperware pot since they reached the appropriate point of staleness (apparently this works better when they’re a bit hard).

We started out with some simple shapes.

I was aiming for fractal tetrahedrons a bit like these, but in my spontaneity I didn’t have the instructions to hand and they were trickier than I’d anticipated!  My creation wasn’t very geometric – good discovery learning, though! (I’ve since read that the trick is to start with a flat base instead of a single tetrahedron).

This activity is a delight for kinaesthetic learners – the  materials make for exquisitely lightweight, tactile shapes that, thanks to the squidgy marshmallows, are strong enough to play around with until you’re satisfied with your shape (or decide to give up, for today, on making a fractal tetrahedron).

C came up with some wonderful – and geometric! – shapes.

It made a fabulous ferris wheel on its side!

Which she “signed”.

J made me think of those creativity tests (“How many uses can you think of for a house brick?”) as he reeled off things his models could be (radiator, ladder, goalpost…)

Creative juices flowing,  J asked if  we could have “Poetry Breakfast”, so we ended up reading poems as we modelled.  It occurred to me how different my children’s first hearing of “Macavity The Mystery Cat” was to my own, in a classroom!

To The Science Museum And Beyond

We celebrated C’s first day being home educated by visiting the London Science Museum. From there, we blasted off in Apollo 16 to the moon (and got wet when we splashed back down to Earth) – and came close up, in the museum’s IMAX cinema, to the swooping dolphins, lurking sharks, super-pods of whales and plunging gannets travelling up the Eastern Coast of South Africa in pursuit of the gigantic-shoals of sardines that migrate north in winter (“poor Sardines”, whispered J (5), in a rare display of empathy).  We also allowed ourselves plenty of time for hands-on science fun in the “Leap Pad” section, always a fC at science museumavourite.C at sci museum IMAX

My Library Thing

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