'What we did' on Friday 7th October 2011
Our main subject matter for the evening was a touch of physics and chemistry
DEMONSTRATION EXPERIMENT- related to chemistry & physics / gravity / ultra violet Light
DEMONSTRATION - Changing Water into Wine and back into Water! - In the first picture there are 3 wine glasses on the table. The first one contains a clear liquid. It was poured into the 2nd glass and it instantly changed to a red colour. This was in turn poured into the 3 glass and instantly changed back to a clear liquid. (The last change was demonstrated at the end of the science club).
The 1st glass contained water with a few drops of sodium hydroxide (caustic soda crystals). Then added a few drops of phenolphtalein to the 2nd glass. Then added a few drops of hydrochloric acid to the 3rd glass.
** How it works ** - The sodium hydroxide makes the water in the first glass alkaline. When you pour the alkaline solution onto the phenolphthalein, a chemical reaction occurs, turning it deep red. When you pour the red mixture into the glass with the concentrated acid in it, the phenolphthalein returns to a colourless form - water into wine, and then back again.
DEMONSTRATION - Burning off Methane Gas in the Artic - Not quite but nearly!
Welcome to Mr Nick Sheehan - Head of geography at Teign Community School, Teignmouth who firstly showed a 2 minute dvd of methane burning in the Arctic Circle. - see link here
Nick then brought us a very dramatic experiment of burning bubbling gas in a bowl of water.
DEMONSTRATION - The Impossible Balance!
How to balance a bucket of water with just a slat of wood a
few mm long. Impossible?
No, not if the centre of gravity can be shifted. Using another
short piece of wood placed vertically the centre of gravity
is moved. (The two pieces of wood are not fixed together).
The bucket is actually balancing with just a few mm of slat on
DEMONSTRATION - 'The Centre of Gravity'. Balancing 2 forks on the edge of a wine glass with a toothpick (can be done easier with a cork), demonstrating the centre of gravity. We even burnt the short piece of toothpick overlapping the glass. See more details here
INTERACTIVE - Air pressure - Holding a glass tumbler upside down full of water supported only by a piece of cardboard. Demonstrating the effect of air pressure and surface tension.
INTERACTIVE - 'Rapid Reponse' - When something happens, how quickly can you react. No-one has instant reactions because there is a split second delay between your brain receiving information and acting on it.
A child held the top of a foot ruler then without warning dropped it between a friends thumb and forefinger. We checked how far up the the ruler it was caught.
DEMONSTRATION - One tiny crystal turns a lquid into a solid. A supersaturated solution has some very special qualities. Sodium acetate trihydrate. It also illustrates an exothermic reaction of the heat of crystalization. See the link here for details
INTERACTIVE - With somewhat less 'stuff' on the tablecloth all of the children who performed the trick did it succesfully. When the cloth is pulled, friction acts on the objects in the direction
of the pull for a short time. The tablecloth is slippery, so these forces are small and the cloth sneaks out from underneath the objects. Amazing! Of course, there is special way to 'pull' the tablecloth off the table.
A CUP OF WATER, A SMALL PIECE OF KITCHEN ROLL, A NEEDLE - Floating the needle on top of the peice of kitchen roll, when waterlogged the piece sinks leaving the needle floating on the water showing surface tension. Also providing the needle was magnetized it floated and pointed north.
INTERACTIVE - 'Make Glowing Water'. The 'Glowing Water' made during last months science club was shown to react in front of a Ultra Violet Light. See more detail here
The October issue of 'making science cool' booklet was handed out
- click here to see pdf copy.
There were other experiments carried out during the course of the evening
making a fantastic time for children and helpers.