Playing (with the Bucky) Ball

As we've enjoyed our Kitchen Chemistry class, I bought this book as a extension to our current interest in chemistry.

The first we looked at was the buckyball, a soluble type of carbon molecule coded C60.

Here's what the man who discovered it has to say about it:

We tried to build a model of the buckyball, first with toothpicks and plasticine but they were too flimsy to stay up.

We then tried to construct the model using magnets.  That didn't succeed either because (1) we didn't have enough magnets to make 60 carbon atoms, and (2) we couldn't hold the molecular structure up long enough to form the ball shape.

Even though we did not manage to put the buckyball model together, we did get a good idea of its properties,

 as well as an interesting history leading up to its discovery:

 While learning about the properties of the buckyball from the good people at the University of Nottingham, we were led to watching the following video about graphene, which is essentially a one-layer, an-atom-thick size of carbon molecules.

The video made us feel a little better because we have at least managed to get a model of graphene, although we did it without realising what we were doing, or that the flat layer has a name!

In the end, to salvage our crumbling sense of self-worth, we put together a model of the water molecule using an orange, two toothpicks, and two plasticine balls.

The clip below shows a quick explanation to the make ups of water molecules and how the different strengths of chemical bonding result in water being in different states.

This post is linked up to:

1. Science Sunday: 10 July Summer Ideas
2. Hip Homeschool Hop - 7/1/14
3. Weekly Wrap-Up: The one with the amazing new dryer
4. The Homeschool Mother's Journal (7/5/14)

The Chemistry of Colours

When I think of colour, I often think of it being a physics topic, as in, the light spectrum.  I had never thought about it in terms of chemistry, until Tiger attended the Spectacular Colour Chemistry workshop at The Royal Institution.

A lot of learning was covered in the workshop so I will try to recapture some of the most salient learning points for us.  The biggest learning point, for me personally, is to start thinking about how our perception of colour depends not only on how light is reflected (everyone knows that, obviously)...

but also how changes in chemical bonding and electrons in specific atoms can result in differences in colours, as perceived by the human eye.

This requires knowing more about the elements and of the periodic table (i.e. atomic mass and charge) so I can't speak any more knowledgeably about it than in very generic terms.

It appears that we need to know the fundamentals about the periodic table after all -- mental note to myself to cover the elements at some point.

I almost broke out in cold sweat in a corner of the room when the instructor started talking about atomic structure and neutralising charges via chemical bonding.

Luckily Tiger was able to hold his own in the class by answering correctly a question thrown at him out of the blue.  The question was to show how a helium atom can be neutralised by altering its mass and charge.  I don't know how he did it, but maybe his reading very widely has something to do with it.  Besides, the question essentially is more mathematical than scientific, so perhaps the mathematical nature of the question helped.

Anyhow, he earned his right to remain in the class.  The rest of the time was pretty easygoing.  Quite a bit of time was spent discussing about the differences between natural and synthetic dyes, followed by some hands-on activities to create natural dye from pomengranates.

The value of being in a dedicated science lab (as opposed to our kitchen lab) is obvious when the children got to create synthetic dye.  It would have been very difficult for me to get hold of the chemicals required to replicate the process at home.

Funnily enough, Tiger was just asking me how food colouring, i.e. synthetic dyes, are made.  He now knows the answer, thanks to this workshop.

Colourful Ooohs and Aaahs

Chemistry is one of those subjects that conjures up the image of a mad scientist playing with wonderfully coloured potions, aided by much fire, smoke, and explosions.  Well, at least that was what I had thought of the subject as a child!  In my school days (that was a very long time ago), we were not allowed to learn chemistry in school until 15 years old, and only to prepare for the O-level exam.  I waited in excited anticipation to start studying my dream subject only to drop it promptly after two lessons when my then-chemistry teacher insisted upon having us memorise the entire periodic table which she would then test us on our memorisation skills in the third lesson before we were deemed "good enough" to conduct any chemistry experiment!  That killed my interest for the subject on the spot.

Tiger's experience with chemistry has, thankfully, been very different.  We approach it in as much a hands-on way as possible.  At this stage, I seek to maintain a healthy level of interest and a sense of curiosity in Tiger rather than to require him to memorise information.  There may come a time when he needs to memorise the periodic table, but not just yet.

In the past six weeks we have been busy following the Kitchen Chemistry course offered by FutureLearn.  Lucinda has written an informative piece about their experience with the same course so I won't repeat the information but I will share some highlights of our experiments from the course.

One of the early experiments to demonstrate rising hot air called for a special kind of teabag that I couldn't find from the supermarkets but we carried on with the experiment using our normal teabag.  Alas, it didn't work.

Next, we explored the concepts of states of matter via physical and chemical changes.  I shall expand more upon the candle experiment (see Lucinda's post for more details on this topic) in a later post.  What I will show you is the standard bicarbonate soda reacting with vinegar video, which is a stanard 'erupting volcano' experiment that many children are familiar with.  One can't go wrong with this experiment!

In the third week we learnt about solubility.  The standard oil-in-water experiment was part of that week's set of experiments.

We found the experiment to separate soluble substances to be particularly interesting, no less because we got to play with the iodine solution, which has become a rare item in the UK since 2009 due to an EU 'recommendation'.

What's facinating in the above experiment is that iodine actually dissolves better in oil, as shown in the righthand-side photo.  If you look closely at the video clip below, you can see the liquids separating:

Tiger then became curious about the density of water versus that of oil, so he dropped a few drops of water using the pipette into the mixture and saw how the water droplets travelled through the oil-and-iodine mixture (at the top) to the water (at the bottom).

Chromatography is an extension of the solubility test.  We did separate experiments using felt-tip pens and food colourings, and found that we had better results with the felt-tip pens.  It may be due to the quality of the food colourings we have.  Nonetheless, the process of chromatography is always very colourful and somewhat magical.

Next, we made red cabbage indicator to test for acids and alkalis using various household items: lemon juice, washing up liquid, table salt, washing soda, toothpaste, and vinegar.

Out of all the items we tested, the most visible change in colour came from the washing soda (sodium carbonate), which is an alkali and therefore turned the red cabbage indicator from light red into a dark green colour almost immediately.

As we boiled a whole red cabbage, we had a large quantity of red cabbage indicator at our disposal so we continued with the acid/alkali experiment using milk of magnesia (an alkali) and vinegar (an acid) to play around with the different levels of pH.

When the indicator was added to the milk of magnesia, the solution turned green, indicating its alkalinity.

When vinegar was added to the solution, the solution turned pink, indicating its acidity.

We also used iodine to test for starch (cornflour mixture).

Using two iodine solutions (one bottle is the control), we added the starch solution to one of them.  The change in colour was immediate, indicating a presence of starch.

The course has given us a reason to take an interest in chemistry again so we will be spending a few more weeks exploring it.


This post is linked up to:

1. Hip Homeschool Hop - 5/27/14
2. The Homeschool Mother's Journal (5/24/14)
3. Science Sunday - 10 June Science Ideas for Kids
4. Weekly Wrap-up: The First Week of Summer Break 2014

Halloween: the sweets

We had a bit of fun looking at how different types of sweets are made, as well as investigating the colour coating of sweets and their solubility.  The idea was taken from here.

At the start of the experiment.

At the end of the experiment.

I thought we could extend the activity above by going into an inquiry-based chemistry curriculum (I much prefer to have some kind of structure going, if I can help it), so we went along and did chapter 1 of this curriculum.

The curriculum itself is well designed and attempts to inspire questions, rather than being a fact-based textbook.  However, very soon I realised that it does not work for us because the questions that the curriculum is guiding the student to ask are not the questions that Tiger is interested in.  Hence, we stopped after stuggling to maintain our interest beyond chapter 1.  Yet another example of a well-intended curriculum plan that does not match the way my son wants to learn.  He is the child who is interested in learning but who is not interested in being taught.  One thing I've learnt from going through the one chapter in this inquiry-based curriculum with Tiger is that he wants to find the answers to his own questions, rather than answering the questions that someone else has set for him.


This post is linked up to:
1) All Year Round Blog Carnival: Autumn
2) Enchanted Thursdays Blog Hop #36
3) Homeschool Mother's Journal: October 26, 2012
4) Collage Friday
5) Favourite Resources: October 26, 2012
6) TGIF Linky Party #53
7) It's a Wrap
8) Weekly Wrap-Up
9) Science Sunday