Sunday, January 30, 2011
Saturday, January 29, 2011
Friday, January 28, 2011
by Melania and Andreea
Materials you will need: food Colouring, liquid dish soap, shallow pan/dish, whole milk (room temperature)
Put some milk into the pan. Allow the milk to come to room temperature. Add a few drops of different coloured food colouring into the pan of milk. Add a few drops of liquid dish soap into the pan of milk. Watch to see what happens.
The fat in the milk is broken down by the liquid soap. This causes the food colouring to swirl and make some really neat designs.
Thursday, January 27, 2011
To this experiment we need: a glass, a water, a coin.
We put coin on the table and cover it with glass. Look! We can see a coin.
After that we pour water .... and now we can't see a coin.
Why? Because of refraction.
by Daiana and Corina
Materials you will need: vinegar.a Bowl, washing powder
Take a spoonful of soap powder and place it in the bowl Add several drops of the vinegar onto the soap powder in the bowl.
This reaction becomes a bubbling froth that gives off carbon dioxide gas. Once it finishes frothing, it leaves behind a salt substance that is not edible (DO NOT eat this salt). This chemical reaction is caused by the vinegar acting as the acid and the soda is the base.
by Miruna and Beatrice
Materials you will need: paper towel , lemon, knife, plastic cup or bowl, dirty/old copper coins
Cut the lemon ans fill the cup/bowl with some lemon juice. Put the dirty copper coins in the juice and let them soak for a few minutes. Remove the coins from the cup/bowl and place on the paper towel..
Oxygen in the air reacts with copper, making a copper oxide coating. This is what makes copper coins dirty. The acid in the lemon juice reacts with the oxide and removes it from the coins – making then shiny copper coin.
Monday, January 10, 2011
glass, water and piece of papre
The glass is filled with water and covered with a sheet of paper. The water does not spill when we rotated the glass, because the paper is sucked to the glass of the pressure.
- a glass or jar
- some tool (we used spoon)
Prepare saturated solution of salt water. Try to mix as much salt in wateras is possible. Put the tool into the glass. (You can also attach a piece of woollen yarn in the middle of the little stick). Put the glass in a warm place for a couple of weeks.
Observe the appearance of salt crystals. The grown crystals are in the shape of cuboids with shiny and smooth sides.
- 2 eggs (1 raw, 1 hard boiled)
- 1 litre jar
The way of carrying out the experiments:
Fill half of the jar with water. Prepare a solution of salt and water. Put the eggs into the solution in which the eggs should sink. Observe the movement of the eggs when a little amount of fresh (sweet) water is being poured in.
Raw eggs has a bigger density than water, that's why it sinks after putting it into the jar with fresh water. Adding salt to water, increases the wieght of water. The weight of fresh water is smaller than the weight of egg. Dissolving salt in water increases the force of uplift which acts on the egg.
Sunday, January 9, 2011
Hit the ruler. The ruler flies away without breaking. Again, lay the ruler on the table and put a piece of newspaper on it so that there is no air under the newspaper. Flatten the piece of newspaper carefully. Quickly hit the ruler again. The ruler is broken.
The air above the piece of newspaper pushes it down with a big force. The ruler isn´t strong enough to lift the piece of paper. When you hit the ruler slowly, there is enough time for some air to flow under the piece of paper and to balance the air pressure under and above the paper.