Korean Job Discussion Forums

[Len8]

I remember seeing students with a compoud of iodine and something else, and throwing it on the floor to make popping noises as the compoud exploded. Anyone out there know what the componds might have been and if possible how to make them.

We are having a science fair at the school I am working at , and I am looking for ways to entertain the students with chemistry.

[mrsquirrel]

Ammonium tri-iode crystals.

NOt the best thing to do for a science fair as they release Iodine vapour which will stain things and is a little bit of an irritant.

[mrsquirrel]

Entertaining experiments.

Get some corn starch/corn flour and show them the classic isothiscoscopsy (can't spell it) and thigmosciscopy experiment.

Mix it until it looks like there is a skin on the surface of the mixture. If you press it hard it will feel solid but if you put your hands into it slowly it is like liquid.

Students can pick it up and squeeze quickly to make a ball of it in their hands. When they let go it will melt.

Conc Suplhuric acid and sugar is good has to be 18M + though. Half a kilo of sugar and 25 ml of acid.

If you can throw things out of windows the egg parachuting is good as well. Two bits of A4 paper and a meter of tape. egg must survive a fall from second floor. Don't instruct Ss but need to let them work out what to do.

[blackjack]

could always make hokey pokey (NZ name it's a type of toffee) Heres a teachers work sheet. we made this stuff in science when i was a kid. might be a bit hard finding golden syrup tho

http://arb.nzcer.org.nz/nzcer3/SCIENCE/MATERIAL/6300-399/Mw6332.htm



Teacher information • There are five parts in this assessment, the first four are done as the process of making Hokey Pokey is carried out. The fifth can be completed at the end.
• Recipe:

Ingredients:

5 Tbspns sugar
2 Tbspns golden syrup
1 tspn baking soda

Instructions
• Use a large heavy based saucepan (cooking pot) as the mixture will foam up – and watch carefully while cooking as it burns easily.
• Bring sugar and golden syrup to the boil slowly stirring all the time.
• Simmer gently over a very low heat for 4 minutes, stirring occasionally.
• Remove from the heat and add baking soda.
• Stir in quickly until it froths and pour at once into a greased tin or onto a piece of tinfoil.
• Break up when cold and store in airtight jars.



a)
Show the students the raw materials: baking soda; sugar; golden syrup. Discuss how substances can be solid, liquid, or gas.
Children draw baking soda, sugar, and golden syrup and label each as a solid, liquid, or gas.
b) Heat this mixture.
Children write a description of this mixture.
c) Add baking soda.
Children write a description of what happens when this is done.
d)
Tip into the greased tin.
Children write/draw and give a taste description of the set Hokey Pokey, i.e., once it has cooled.
e) Give children the second assessment sheet of words and changes in making Hokey Pokey.