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In a vacuum would a solid turn to liquid quicker?
- Brandon Hoy (age 12)
Usually lower pressure favors the liquid state over the solid, since the liquid usually occupies more volume. (Water is an exception.) However, at very low pressure, the gas phase, which occupies much more volume, is favored over both. In a vacuum, many solids will sublime- directly evaporate to the gas, without becoming liquid.
You still need energy input to cause the sublimation process to happen. Comets are balls of different kinds of ices and rocks and metals, and meteors and asteroids are stable under sublimation on time scales of billions of years.
(published on 10/22/2007)
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