Ice-A big model for an important molecule.

Ice, Not Just H2O Under
Bridges: Molecule Monday

Inuktituk, the language of the Inuit (indigenous peoples of the Arctic) has over 50 different words for ice and snow. To the rest of us it is essential for sport, soothing aches and pains and making bad scotch drinkable. Read more about the crystal we can’t live without. 1

Sinking Ice Cubes-1 Drink Too Many?

If you’ve ever tippled overproof rum , you’ll know it packs quite a wallop…you might even think you imagined seeing ice cubes sink in it.  You did! They float on water but sink in alcohol due to the density difference. 2

ice-cube-water-alcohol
Put an ice cube into over proof vodka or rum, watch it sink. Add some water and see it float. You can try this also with rubbing alcohol but don’t drink it!!!

Most Important Space Molecule?

Whenever distant planets are discovered one of the first questions asked is whether they have water. On Earth, we take this for granted but comets brought most of our ~1.5 billion cubic kilometres of H2O, now solid, liquid and vapor.

Imagine an early Earth 4 billion years ago being bombarded by 3 million comets the size of Halley’s. It changes your perspective and gives a whole new meaning to hailstorms. 3

halleys-comet-1986
Halley’s comet has a period of 75-76 years and holds an estimated 500 cubic km of water. It would take nearly 3 million such comets to hydrate planet Earth.

Hard as Diamonds?

Diamonds are sometimes called ice  but their crystal structures, refractive indexes and of course hardness are quite different. Diamond has a MOHS value of 1600 compared to 1.5 for ice. However, the biggest rough diamonds discovered are the size of a fist. Compare that to glaciers capable of gouging out rock and reshaping landscapes. 4

Titanic hits an iceberg
Ice might not be as hard as diamond but as the Titanic discovered, if you ram into a big enough piece of it, the consequences can be disastrous.

The Ice Mirror?

Climate change is a contentious issue to some and the decrease and increase of the Arctic and Antarctic icecaps provides ammunition to both sides.  Ice, snow and cloud all contribute to the albedo or reflectivity of the Earth. The higher it is, the more light and therefore heat is reflected back into space. 5

arctic-antartic
Compare the Arctic & Antarctic ice caps; are they growing or shrinking and what do they tell us about climate change?

No Ice? Not Real Hockey!

If you live in the northern parts of our planet, chances are good you’ve gone skating on ice in a rink or on a canal but did you ever wonder how it works? The pressure of all your weight on a narrow skate blade causes the ice to melt which allows you to glide almost effortlessly. Once you pass over that spot, the water refreezes. This process is known as regelation. 6

canada-russia-hockey
Keep your stick on the ice. Sage advice from Red Green.

Icy Structure from a Volcano

The structure of ice is familiar but it shares a striking similarity to a mineral produced in volcanoes at 5000C. The mineral tridymite occurs naturally on Earth but nowhere else in the solar system, or so it was thought. Tridymite has since been discovered on Mars which raises new questions about the geologic history of the red planet. 7

tridymite silicate structure model
Ice and the silicate tridymite share the same FCC (face centered cubic) crystal lattice structure.

Big Molecular Model

We’ve supplied ice molecular models in the Orbit and Molymod styles for years. Our most recent addition is done in the Unit Model style which features atoms measuring 45mm across. compared to the 10 & 23mm respectively for Orbit & Molymod. This enlarged scale allows us to build bigger structures that are useful for teaching or as museum displays.

unit-ice-69205
This is our really big model of ice done in Unit style. The version shown here measures nearly 500mm (20 inches) across. All parts can be interchanged but this is rarely needed since they are much stronger than old style styrofoam based models.

References

  1. Inuktituk
  2. Density of Ice vs Water
  3. Comets
  4. Hardness of Ice vs Diamond
  5. Earth’s Albedo & Climate Change
  6. Regelation
  7. Tridymite on Mars

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