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Old 29th February 2004 | 15:07
  #40 (permalink)  
bookworm
 
Joined: Aug 2000
Posts: 3,648
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From: UK
On the sublimation question, consider the following cases:

1 A liquid turns (completely) into a vapour at a temperature and pressure associated with the two-state phase equilibrium on a phase diagram. That is usually called boiling.

2 Some liquid turns into a vapour when a dry air stream blows over it at a temperature and pressure associated with the liquid state on a phase diagram. That is usually called evaporation.

3 A solid turns (completely) into a vapour at a temperature and pressure associated with the two-state phase equilibrium on a phase diagram. That is usually called sublimation.

4 Some solid turns into a vapour when a dry air stream blows over it at a temperature and pressure associated with the solid state on a phase diagram. What do we call that?

I don't believe there is a special word for it. Some sources indicate that evaporation is reserved for transitions from the liquid state, though that seems inconsistent with processes of creating thin films of metal and semiconductor in ultra-high vacuum, which is customarily called evaporation.

Sublimation doesn't seem to be reserved for case 3, and I don't see why it shouldn't be used for case 4 too, if you want.

Now I'm no scientific lexicographer, but... no hang on, erm, I am a scientific lexicographer, and my opinion FWIW is that it really doesn't matter whether you say that it sublimes, sublimates or evaporates. The problem for pilots is that it happens painfully slowly!
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