[Jetboy2]

Hi,

Try a simple experiment with your niece. It'll be fun, and she'll love it. And you didn't say the age of your niece, but I'm assuming pretty young, considering the question.

Take 4 glass containers. Put hot tap water in 2 of them and cold tap water in the other 2.

Now for the other ingredients. 2 equal pats of butter/margarine and 2 teaspoons of sugar.

So, put 1 pat of the butter into one of the "hot water" containers and 1 teaspoon of sugar into the other "hot water" container. Likewise, put the same into the "cold water" containers. See what happens.

(You could also add 2 more containers where you add detergent to both the hot and cold water.)

Anyway, little kids usually don't really care about explanations of molecular energy levels and whatnot. And I think that if you do this experiment with her; she'll no doubt, figure out the idea of why hot water works better for washing dishes.

The folks here can surely provide the physics/chemistry of how it works....

jb