The aspiration of children to knowledge of the physical and chemical phenomena can be satisfied even in kitchen. Usual salt, water, potassium permanganate and citric acid are capable to awaken in soul of the child of the young researcher and experimenter.
For young physicists
"Why the lemon does not sink". Experience will require the container with water and the whole lemon. Lower fruit in water, make sure that it did not fall by a bottom. This fact by the fact that a lemon peel porous and contains a large amount of air which helps to remain on a surface is explained. The same principle works in a case with the ice lowered in water. "Deliquescence" of ice is provided with the frozen parts of air. Now clean a lemon and ship in water, because of increase in density it will fall by a bottom.
"Water evaporation". Pour water into two identical glasses, close one of them a cover. Put both containers on a windowsill, in the sun and for couple of days forget about "wards". Several days later compare in what glass there is more water. Explain it to the child with ability of water to evaporate at temperature increase and the fact that the cover did not allow to run away a droplet from a glass.
In bank of water part 2 tablespoons of salt, lower egg. Egg will emerge! Explain to the child that salty water has density capable to hold egg on a surface. Gradually add clear water in bank, reduce liquid density until egg does not fall by a bottom.
To young chemists
"Invisible letters". Experience is well-known from adventure and detective novels. On the sheet of paper draw with milk the drawing or write the text. After drying heat a leaf over fire, and – oh, a miracle! Your message will stop being invisible. A similar experiment can be conducted with lemon juice. Apply the encrypted message on the sheet of paper lemon with juice or the divorced citric acid. In water dissolve several drops of iodine and apply on paper. Letters will become same accurate, as well as in a case with milk. "Live gelatin". 20 g of dry gelatin fill in ½ glasses of cold water. After swelling establish capacity on a water bath and heat to 50 degrees Celsius. Pour out the received weight on cellophane and allow to dry. Cut out a figure from a gelatinous plate and put on the sheet of paper. Breathe on a figure, and it will begin to move. The reason is that your breath heats gelatinous weight and humidifies it on the one hand. Jelly increases in volume a little and moves. "House crystals". Prepare strong solution of salt so that the new portion of salt in it was not dissolved. From a wire collect a framework, lower in hydrochloric solution for several days. After time you will see how crystals of salt accrued on a framework. At sufficient patience ship an object repeatedly, crystals will increase, and you receive fine creation.