Molecules and Crystals in the Ski Patrol Hut

Science at the Top of the Lift

1At Granite Peak ski area, a group of teenage junior patrollers helps the ski patrol on weekends. Their base is a small hut at the top of the main lift. On a snowy Saturday, patroller Leena Halonen brought a molecule model kit to the hut to show juniors Tomasz Wójcik and Zuri Mwangi what some of the things around them are made of.

2In the kit, black balls stand for carbon atoms, white balls for hydrogen atoms and red balls for oxygen atoms. Short rods stand for the bonds that join atoms. Each black ball has 4 holes, each red ball has 2 holes and each white ball has 1 hole. In a finished model, every hole holds a rod, and every rod joins two balls.

3The hut has a small camp stove that the adult patrollers use to melt snow for hot drinks. The stove burns gas from a canister. The liquid fuel inside must boil into a gas before it can flow to the burner. Summer canisters usually hold butane, and winter canisters often hold mostly isobutane. Both fuels have the formula C₄H₁₀. Tomasz built both molecules. In his butane model, the 4 carbon atoms are joined in a row. In his isobutane model, 3 carbon atoms are each joined to a central carbon atom. In both models, hydrogen atoms fill the rest of the holes.

4Some substances in the hut are not made of separate molecules at all. Leena described three of them. In the snow on the roof, each water molecule keeps its 2 hydrogen atoms joined to 1 oxygen atom, and the molecules link up in six-sided rings that repeat in every direction. The blade of the snow shovel is aluminum. It contains only aluminum atoms, packed in a pattern that repeats all the way to the edges of the blade, with no small separate groups. The ice melt that the patrol spreads on the hut's steps is calcium chloride. In each pellet, calcium and chlorine particles repeat in a pattern in every direction, with 2 chlorine particles for every calcium particle.