why is there less ice in the ice tray when you check it 2 weeks later?

Answer 1

It's sublimating.

Sublimation is when a compound goes directly from a solid to a gas. Like evaporation, but not.

Source from the USGS added for ice sublimation.

Answer 2

Sublimation isn't the whole answer (although this is the physical process that occurrs). To answer your question of WHY ice sublimates in the freezer, you have to think what a freezer is: it is a heat exchanger, drawing heat from a hotter place, and transferring it to a colder area. In a freezer, the heat exchange takes place at the freezer wall. So heat is transferred from the hottest area (the ice) to the coldest area (the freezer wall). This provides the heat exchange to cause the ice to sublimate, and re-condense on the freezer wall. As Dan S noted, 'frost free' freezers may remove the sublimated water vapour from the fridge, keepi ng the freezer free of ice build up, but allowing more ice to sublimate. I imagine therefore, that you will lose your ice more quickly in an automatic defrosting freezer.

Answer 3

Actually, Dan S is wrong and ice does sublimate under ordinary conditions. Sublimation is simply the movement of molecules from the surface of a solid to vapor. If the air is dry, then melting does not have to occur. In frost free refrigerators the air is very dry and conditions are worse. In the great outdoors, snow that is in shade and not struck by sun, if no more snow falls, gradually gets less and less even if the temperature stays well below freezing because of sublimation.

Answer 4

Because most modern freezers have defrost capabilities. They occasionally thaw to a temperature over that of freezing and a fan blows wind inside of the freezer. This wind is then collected an run through a dehumidified to remove the water. This cuts down on the ice build up, but it also makes it hard to keep ice cubes in the freezer for very long.

Ice or frozen water doesn't sublimate, it turns directly into a liquid not a gas. To cause sublimation the freezer would have to boil your frozen food and they don't do that.

As for d_cider1 why bother to write an answer if you aren't going to even make an attempt to seriously answer the question. You are just going for the cheap and easy points and that is cheating.

Answer 5

Evaporation will still happen unless your freezer can maintain absolute zero. Water molecules are still moving, and can fly off the surface at the 24-28 degree F your freezer maintains.
(just keeping it simple)

Answer 6

Sublimation - the solid water is directly becoming vapor.

Answer 7

You got ice out a week ago, and forgot.