'What we did' on Friday 9th September 2011
Our main subject matter for the evening was a touch of physics and chemistry
MAIN DEMONSTRATION EXPERIMENT- chemistry - we made ELEPHANT TOOTHPASTE.
A very dramatic presentation of adding Potassium Iodide to Hydrogen Peroxide, with a few drops of concentrated detergent and food colouring. Two x 8 foot high columns of bubbles and froth.
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 - Magnets - Lots of magnets including some very strong Nyodymium. Magnets showing 'North' & 'South' poles. 'Opposite' poles attract, 'Same' poles repel. Patterns are created with magnets when placed underneath a piece of paper holding a quantity of iron filings.
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.
INTERACTIVE - 'Gravity and Water' - We showed how to syphon water using a small plastic pipe. Water in a jar placed slightly higher then an empty jar was syphoned using a small plastic pipe.
INTERACTIVE - 'Water Molecules on the Move' The experiment proved that hot water molecules really move faster than cold ones. A clear glass filled with hot water compared to a clear glass filled with cold water. A drop of food colouring was added to each and children watched how quickly the food colour dispersed. The food colouring in the hot water moved around quicker than in the cold water.
DEMONSTRATION - 'Escaping Water' 2 jars side by side , one filled with water. How to get water into the empty jar without moving the jars. We twisted a small piece of paper towel, placed one end in the full jar and the other end in the empty jar. After a few minutes the paper towel starts to get wet and then the empty jar starts filling with water.
The process is called 'capillary action', the water uses this process to move along the tiny gaps in the fibre of the paper towels. It occurs due to the adhesive force between the water and the paper towel being stronger that then cohesive forces inside the water itself. This process can also be seen in plants where moisture travels from the roots to the rest of the plant.
INTERACTIVE - 'Make Glowing Water'. With adult help each child cut a highlighter pen in half to obtain the inside fibre. This was taken out and placed in a jar half full of water. After much stirring it was left to soak up all the colour. This is a non toxic flourescent solution which when brought uner Ultra Violet light reacts and glows. See more detail here
DEMONSTRATION - 'Burning the Oxygen' inside a jar standing in a saucer full of water. This demonstrates not only the using up of all the oxygen but also the expansion and contraction of gases. Click here for information. See more detail here
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
The September 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.