Monday, March 9, 2009

9 March 09

D E N S I T Y O F I C E V S W A T E R
----->>which is denser?
Ans: Obviously water. Ice floats on water and this verifies that water is denser than ice. If ice is denser than water which is NO of course, i think you would see water floating on ice which is like HOW??






close up on a water moleclue
----->>why is it more painful to throw ice cubes instead of water?
Ans:In water, there are always water molecules-without fail-that has a positively charged side and a negatively charged side and like a magnet,it would stuck to each other in a regular pattern that forms a hexagon (six-sided figure.And thus, in ice, the molecules are more 'together' as compared to water which is loosely attracted as they are not frozen-in that sense that the molecules are not frozen which (the shape) is made permanent.Thus, when the molecules is frozen, it becomes hard as compared to water where they are not given a definite shape.

----->>whether water level changes or not when ice is melted in a cup of drink.
Ans:(ACCORDING TO RESEARCH), the water level does not rise as when ice is melted, it takes less volume in the glass.
Personally: I think what they meant in this case is only a small amount of ice but when i put ice in the cup and leave it for a while,you can see a layer of water (in this case the liquid i use is coke)on it. But i thought that the water level increased.Maybe it is due to some evaporation that occured.

----->>effects in boiling point and freezing point/effects of impurities on water Ans:Defination of impurities first:it is the substances inside a confined amount of solid, liquid, gas.melting point decreases with pressure and increases with impurities(eg.sawdust).boiling point increases with impurities and also increases with pressure.

----->>examples of impurities
Ans:ash,debris in metal,leaf pieces in paper,alloys

CREDITS
http://www.exploratorium.edu/ronh/cool_experiments/index.html
http://wiki.answers.com/Q/What_are_the_effects_of_impurities_in_boiling_and_freezing_point
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