Shown here is a portion of the phase diagram for phosphorus.

(a) Indicate the phases present in the regions labeled with a question mark.

(b) A sample of solid red phosphorus cannot be melted by heating in a container open to the atmosphere. Explain why this is so.

(c) Trace the phase changes that occur when the pressure on a sample is reduced from point A to B, at constant temperature..

Transcribed Image Text:

P 43 atm Solid red P T B 590 °C (?)