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Name:   Samantha S.
Status:  student
Age:  15
Location: N/A
Country: N/A
Date: 2000
Question:
Do particules in liquids always move and when you mix two liquids together, the particules collide and thats what causes a reaction?

Replies:
Samantha,

In the world of molecules, heat makes them move faster; cold allows them to move slower. The motion never stops except at an extremely cold temperature of about - 460 F. You may already know that water boils at 212 F and freezes at 32 F -- room temperature is about 70 F. As you can see, those temperatures are far above - 460 F. This means that molecules of everyday things are constantly moving -- even when things like liquids are frozen.

What this all means as it applies to your question: When you mix two liquids together, both before and after mixing, the molecules are in constant motion, Yes, they do collide with each other and yes, those collisions do help in the mixing process.

Try this experiment: Get a plastic soda bottle, remove the label if it has one, rinse it out with plain clean water. Fill the bottle with cold tap water until the water level is very close to completely full. Screw on the cap, dry off the outside of the bottle and it aside for at least a full day. Allowing it to stand undisturbed will enable all the circulation currents introduced when you filled the bottle to settle down.

Without disturbing the bottle -- do not move it in any way, Carefully remove the cap and add a single drop of food coloring to the water. Do not stir the water or move the bottle -- just let a tiny drop of coloring land on the water.. Carefully replace the cap and again allow the bottle to stand. It is important that you do not move the bottle. We want the water in it to remain completely undisturbed.

Examine the water in the bottle over a period of a few days and I think you will be surprised at what you see. Even though the water appeared to be standing quite still, the molecules of water and coloring weren't.

Regards,
ProfHoff


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