Science for Kids/science


why does water expand when you put it in the freezer?

Hi Lola
   This is one of the mysterious properties of water. It has to do with two things about water, the density and the geometry or shape of the molecule of water. You probably know that all molecules are constantly moving. The closer the molecules are the more dense the material is. AS the temperature drops water molecules get closer together or more dense then at 4 degrees it reaches its maximum density and the molecules start to move away from each other and expand becoming a solid and less dense then the water. Anything that is less dense then water floats. It seems that the density at 4 degrees becomes less because the water molecule is not a sphere.If this did not happen there would be no life in lakes and seas because water would freeze from the bottom up and as the weather got warmer it would never thaw completely.

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walter hintz


I can answer questions from kids in all grades in the areas of general science, biology and nature study


I have been a teacher for over 55 years and have spent many years doing hands-on science with elementary and middle school students.

The Ohio Journal of Science
Momentum: The Journal of the Catholic Educational Association

B.S Ed Kent State University
M.Sc. The Ohio State University

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