Sharing the science of snow

Happy new year to you all. I was very happy to see the snow we received last week because I love solid water, and all the things we can do with it. Sliding with my grandkids, riding a snowmobile, skiing at Mont du Lac, jumping and skiing at Pine Valley, fishing on a frozen lake, skating across a pond or a rink, or just looking at it, are all some of the reasons why I really do enjoy winter.

In some of our past adventures we traveled in time or became really small. This column is about snowflakes; we need no special powers to enjoy these beauties and just a little chemistry and physics to understand how a snowflake forms.

To best get into snowflake formation, we need to understand the amazing water molecule. We all know the formula H2O, two hydrogens and one oxygen. My first drawing (Drawing 1) shows the shape of the molecule and the charges on it. Notice that a water molecule has a positive side (hydrogen), and a negative side (oxygen), and that it is a bent molecule. The causes of the charges and the bent shape would take too long to explain for this crazy little column.

Drawing 2 shows how water molecules are attracted to one another. Remember opposite charges attract, so the hydrogen of one molecule is attracted to the oxygen of another: this is called a hydrogen bond. When temperatures are warm, the molecules are moving too fast for the hydrogen bonds to hold, so the water will be in liquid or gas form. When temperatures are lowered enough, the molecules slow down and the hydrogen bonds can hold. The molecules then start to line up like little soldiers. The angle of the bend in the molecule is about 104 degrees, and this angle plus the hydrogen-oxygen attraction creates the hexagonal crystal that can be the beginning, or a part, of a snowflake; check out my drawing 3.

Next time it is snowing, don't just think about catching a snowflake, actually catch one and look at it - they are pretty amazing in person.

Next week my wife and I are off to Hawaii to join my daughter, son-in-law and grandkids. It will be my first trip there. It may not be Carlton County, but the formation of those islands is a great story. More on that to come.

FDLTCC science tutor Glen Sorenson was Minnesota Teacher of the Year before he retired from teaching science at Proctor High School after 30-plus years. He is an avid outdoorsman who most recently coached the Lumberjacks Nordic ski team.