Question

How does ice form on a window pane if there is no water?

Asked by: Martin

Answer

Ice, being frozen water, CANNOT form if there is no water. Ice on a window pane is most often formed from the water in the air contacting it.

You know from weather reports about "relative humidity", which is a measure of the amount of actual water vapor in the air compared to the maximum amount of water vapor the air can hold. Warmer air can support more water vapor than cold air. As warm air comes in contact with a cold window pane, it's temperature is lowered and the water vapor that it can no longer hold condenses. If the temperature of the pane is below 0°C (32°F). that water freezes to become ice on the window pane.

Home humidifiers usually come with instructions NOT to raise the humidity level to the point where water (and ice) form on windows, since damage to wooden frames can occur.

Answered by: Paul Walorski, B.A., Part-time Physics/Astronomy Instructor

Search

Loading



Click here to get
a FREE ride with Uber!


Click here to
sign up for Birchbox






Science Quote

'As long as men are free to ask what they must; free to say what they think; free to think what they will; freedom can never be lost and science can never regress. '

J. Robert Oppenheimer
(1904-1966)
Science Sidebar | Science Education Articles
10 Ways to Keep Your Kids Interested In Science

Young children are natural scientists: they ask questions, pick up sticks and bugs outside, and are curious about the world around them. But as they get a bit older, many kids gradually lose their interest in science. They might see it as just another task at school, something that doesn't apply to their lives. Of course nothing could be further from the truth, so here are ten ways you can remind your kids that science is everywhere. Most of these are fun for adults, too! Continue reading ...

Top Selling

Here are our physics & astronomy bestsellers:
Deluxe Water Rocket Set
Magnetic Levitator - Classic
Scorpion, Ant, Wasp and Flower Bug
12 inch Galileo Thermometer
Revolving Multi-Color Fiberoptic Light
Solar Radiometer
Enviro Battery 4M Kit
Tin Can Robot 4M Kit
Wood Grain Newtons Cradle
Brush Robot 4M Kit

Sponsors

USC University of Southern California Dornsife College Physics and Astronomy Department McMaster University Physics and Astronomy Department