Antarctica/Exploration ICEBLOCK/Teachers Backpack/Experiments with ICE

EXPERIMENT: MELTING ICEBERGS


This experiment enables children to predict, observe and explain what happens to the water level when floating ice melts.


 * Put an icecube in a glass of water.
 * Mark the water level on the outside of the glass with a whiteboard marker.
 * Predict what you think will happen to the water level when the icecube has melted. Try to explain why you think that will happen.
 * Leave the floating 'iceberg' until it has melted then go back and observe what has happened to the water level.
 * Explain what you observed and why this happened.



NOTE FOR TEACHERS: Icebergs and sea ice melting do not affect the sealevel because the water is already displaced with the floating ice. However, ice melt from a land base will cause sea-level rising. If children want to pursue this inquiry they could try a similar experiment but this time with a block or rock that sticks out of the water (simulating land mass) and an icecube on top of that.



EXPERIMENT: SEA ICE BREAKDOWN


This experiment helps children appreciate that not all things freeze at zero degrees celcius (0°C) like fresh water does. If necessary discuss the freezing point of fresh water, perhaps relating it to frosts in winter.


 * Make samples of fresh water, slightly salty water, salty water and very salty water.  (Let the children experiment with amounts of salt they use in each solution, perhaps discussing the aspects of a 'fair trial'.)
 * Place each sample in either icecube trays or other containers suitable for freezing and clearly label each sample.
 * Place samples in the freezer and observe results at say half an hour, 1 hour, 2 hours, next day.
 * Predict what you think will happen and explain why.
 * Remove samples from the freezer the next day and observe what has happened.
 * Explain your results.

 NOTE FOR TEACHERS: Sea water freezes at minus two degrees celcius (-2°C). This is because the salt molecules in the water essentially slow down the ability of the water to freeze, so the icecube eventually melts unless the temperature is increased. If the water is very salty it will require even colder temperatures to freeze. A good explaination with diagrams to help is given in the following link: Explaination and Application of Salt and the Freezing Point of Water