Question

when a few of crystals of iodine place in a dry test tube, heat the tube and note the changes . cool the tube.
what happens when the tube is heated?
does any iodine melts?
what is formed in cooling the tube?
what is this process called?
define it?

Answer 1

Answer:

in the above example it has been shown the process of crystallization. on heating the colour disappears and on again adding the water cooling it the colours come up this process is called crystallization

.

Answer 2

Answer:

when testtube heated the oxygen will disappear

this process called crystallisation