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)

What a State!

Following our recent interest in chemistry, lectures and workshops related to chemistry suddenly seem very relevant so we signed up for a whole bunch of them.

The first workshop was a short one devoted to explaining the states of matter to upper elementary-grade children.  The workshop leader explained about the differences between a physical and a chemical change and whether the reactions involved are reversible.

There were a few demonstrations on how different states occur but the coolest one was when he froze a fresh banana rock solid using liquid nitrogen.  At the end of the workshop, he poured what was left of the liquid nitrogen out onto the floor, which promptly turned into gas.

We also attended a number of chemistry-related lectures at The Royal Institution.

Lectures at the RI are always very accessible and interesting.  Of course, it helps when the demonstrations involve loud noises and explosive visuals.

The content of one of the lectures that we attended is very similar to the one shown below:

We also decided that, instead of just watching other people having fun with the experiments, we ought to try some safe-to-do-at-home ones ourselves by consulting the following books:

We made some sugar crystals by suspending a piece of cotton rope into a glass of water saturated with dissolved sugar for 24 hours;

Tiger marveled at the work of air pressure to hold the thin piece of card up under the weight of water in the jar;

and fishing ice out of water using a piece of string (and a little salt to melt the ice).

In the clip below, you can see the ice being suspended above the water by the piece of string on one side.  That's pretty cool.

To my surprise, the activity that really captured Tiger's interest involved him drawing a road map for his 'magnetic' cars (car shapes cut from paper with a paper clip attached to the back) to move around.

We attached a small, round magnet onto a ruler, then off the paper vehicles went.  Of course, one of the vehicles has got to be a tank.

I, on the other hand, was found the raisin-in-soda trick mesmerizing.

I call it 'the poor man's lava lamp'.  I literally sat at the table and watched the raisins go up and down the jar for more about 20 minutes until all the fizz was gone.  I reckon it would be a very good trick to keep a three-year-old occupied long enough for mum to have a cup of tea in peace.  I wish I had known this trick when Tiger was three years old!

While we were in the fizzy drinks isle, Tiger asked to pick up an extra bottle of diet soda to do the soda foundation experiment that we had done a few years ago.  Well, one can't say no to this simple request!  This time, we also looked into the science behind the experiment.

This post is linked up to:

1. Hip Homeschool Hop - 6/3/14
2. The Home Education Weekly Link Up
3. Weekly Wrap-up: The One Before Date Week
4. The Homeschool Mother's Journal (6/7/14)
5. Science Sunday - How to Make a Brain Cell Model

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

Different Ways with the Water Cycle

Our river study naturally leads to learning about the water cycle.

A 50p charity shop find of a strategy game based on river tides.

It is truly amazing to discover the interconnectness of various seemingly random topics, but somehow we have been able to stretch our themed study of The Wind in the Willows further and further.  The rest of the series can be found here.

Desk Learning
We started off by printing off the water cycle exercise from here.   First, Tiger matched the labels to their definitions, followed by labeling the diagramme.

Since we had not covered water cycle formally before, I wanted to use the exercise above to gauge how much Tiger knew or didn't know, so that we could focus our efforts on learning new things rather than unnecessary repetition.  When Tiger needed a bit of clarification on the processes, we watched the clips here and here.

Finally, we worked through the section here for review and to test our understanding of this topic.


Hands-on Experiments
Enough of table-learning!  Time to get some hands-on work done so we did a few experiments related to our topic.

1) The classic experiment

Procedure:

1. Bring a pan of water to boil.  Observe the air bubbles in the pan and the steam (photo 1).
2. Put a few ice cubes in a foil tray and hold it above the steam - be careful not to get burned by the hot steam! (photo 2)
3. photo 3: Observe the moisture that forms at the bottom of the foil as the warm air meets the cold foil surface. (photo 3)
4. As more steam/vapour gathers on the bottom of the foil, the water molecules gather to form bigger drops which eventually fall. (photo 4)

2) Water cycle in a bottle

Procedure:

1. Cut the neck of the bottle and screw the cap on tightly.  Pour a cup of warm water into the bottle and place the top of the bottle as shown.  Use cellotape to seal the space where the two parts of the bottle meet.  Place the bottle under direct sunlight for 5 minutes.  Think about what will happen to the air temperature in the bottle as it is exposed to the sun.  Observe the inner surface of the bottle and the bottom of the funnel (we observed some condensation on the sides of the bottle but none on the funnel). (photo 1)
2. Put some ice cubes in the funnel and observe for 10 minutes.  Think about what's happening to the air temperate around the bottom of the funnel. (photo 2)
3. After 10 minutes we observed condensation on the bottom of the funnel as well as on the sides of the bottle. (photo 3)

3) How raindrops form

Another simple and potentially safer way (compared to experiment 1) to observe "raindrops" forming.  This simple experiment is done by pouring enough water into a jar to cover the bottom, then place a few ice cubes on the inside of the lid and put it over the mouth of the jar.  After 10 minutes you'll see water droplets forming on the underside of the lid.  It works on the same principle as experiment 1: water vapour (from the room-temperate water at the base of the jar) rises in the jar then condenses as it touches the cool underside of the lid.


4) How water droplets gather in clouds

This experiment expands on the previous one (experiment 3).  Tiger first squeezed many separate drops of water onto the inside of a plastic lid, then quickly turned the lid over.  He then used the tip of a pencil to move the tiny drops of water together.  What he observed was the drops seemed to pull one another together to form larger drops.  When the drops are quite big, they fell.

The attraction of the water droplets is due to water molecules having a positive and negative side, similar to how magnets attract each other at opposite poles.


5) How the Water Cycle Purifies Salt Water

Procedure:

1. Stir 1 tsp of salt into a glass of clean water.  Dip your fingertip into the salt water and taste it. (photo 1)
2. Add several drops of food colouring (we used red, blue, and green) into the salt water and stir it well. (photo 2)
3. Put the cup in a ziplock bag and zip the bag up.  Place them in the sun.  Observe the bag every 5 minutes for any changes. (photo 3)
4. After 15 minutes, we observed some colourless condensation inside the bag.   We also tasted it and found it to be tasteless. (photo 4)

Field Trip
We attended a workshop at a water treatment plant where the children were given a quick overview of the water cycle.  As the workshop was conducted at a water treatment plant, the water cycle exercise included an extended part about how water is collected and treated before becoming clean enough to come out of taps in people's homes.

The children also spent some time investigating changes in the types of organisms found in rivers and water supply due to changes in the level of pollution/industrialisation over time.

Next, it was time to head outside for a tour of the premise. 

A disused filter bed.  You can still see the water tank and pipe from Victorian times.

Much of what we saw were historical -- what the Victorians used for filtering the water supply to London.  For example, we went to an area called the Central Wellhead, which was where the cleaned water (after flowing through the pipes onto the filter beds from the surrounding reservoirs) was stored before being pumped into the water mains.

What I found to be most interesting was seeing an area of preserved filter beds.  The centre has allocated several beds to be preseved in different stages to show they changed over time.

Open Water - This filter bed looks much as it did when it was actively being used.

5 years on - When the filter bed was abandoned, the water level began to drop.

10 years and more - As more sand and gravel was exposed, the plant cover become more densed.

Deeper water - Not all the water drained away from the filter beds.  Tall water plants like reeds will grow where deep pools of water are retained.  Reed beds create a different type of habitat for birds.

25 years and more - Much of the water would have drained away, causing a wet meadow to develop.

30 years on - If the filter beds were no longer managed in any way, ash, willow, and elder trees would eventually grow on them, thus creating a woodland habitat.

The children were shown a simplified version of the filtration process using soil, bottle and water.  I wanted Tiger to conduct the experiment himself rather than passively watch someone else do it, so we did the same experiment when we got home:

Procedure:

1. Use the same bottle as in experiment 2, but this time remove the lid and cover the inside of the funnel with a piece of coffee filter paper. (photo 1)
2. Fill the coffee filter paper about 3/4 ways to the top with sand. (photo 2)
3. Dampen the sand with some clean water. (photo 3)
4. Mix soil and water together a jar. (photo 4)
5. Pour the muddy mixture through the sand carefully. (photo 5)
6. Observe the clean(ish) water being filtered into the bottle. (photo 6)

By conducting this simple experiment at home, we could see the filtration process up-close.  Even though we knew what result to expect, we still found it fascinating to see muddy water become clear water collected in the bottle.

This post is linked up to:

1. Look What We Did
2. History and Geography Meme #92
3. Collage Friday: Signs of Fall
4. Entertaining and Educational - Sept 27
5. Field Trip Friday Link Up
6. Homeschool Review and Resource Link-Up
7. Weekly Wrap-up: The One with a Little Encouragement
8. Science Sunday: Learning about Muscles
9. Hip Homeschool Hop - 10/1/13