5
$\begingroup$

Carbon has no liquid form at atmospheric pressure. Is this unique amongst naturally occurring elements?

The more interesting and vague question is, is this property somehow important or related to the many other amazing properties carbon has on Earth or just a coincidence?

$\endgroup$
7
$\begingroup$

Have a look at a generic phase diagram, for a compound with one solid phase, one liquid phase and a gas phase:

            enter image description here

For the solid to go directly into the vapor phase (sublimation) at ambient pressure upon heating, you thus need its triple point to have a higher pressure than atmospheric pressure, i.e. ~1 bar.

Looking at this partial table of element triple points, arsenic is another element that sublimes at ambient pressure. Iron would seem to qualify, but it has more phases that reported in the table, and the full phase diagram indicates that it does not sublime at ambient pressure.

$\endgroup$
  • $\begingroup$ IODINE! gotta love purple fumes :D $\endgroup$ – Tomcat Aug 31 '13 at 23:48
  • $\begingroup$ @Snipergirl You can sublime iodine by heating, because it melting point and boiling points are close, but technically it doesn't sublime at ambient pressure… you can find an intermediate temperature where you will obtain the liquid $\endgroup$ – F'x Sep 1 '13 at 7:04
  • $\begingroup$ @Fx oh wow! Did not know that! there you go :) $\endgroup$ – Tomcat Sep 1 '13 at 9:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.