Somethings burn while others melt when subjected to heat. Curious observation!! Ever wondered why does this happen? That’s what we will be addressing today in our article. To make things simpler for our audience who are already into science is that burning and melting are two different physical phenomena altogether.
The burning of things or materials is a chemical process and melting is related to a scientific phenomenon called phase transition. You must have observed that when we light a candle the wick of the candle burns whereas the wax (fuel) melts. Burning here is purely a chemical and thermodynamic process whereas melting of wax is phase transition.
For sake of better understanding lets also take an example of burning a piece of wood and melting of ice. See when you burn a piece of wood to ashes can you again convert it back to wood? No, you can’t, this is an irreversible chemical phenomenon. But ice, when melted to water, can be again made into ice. This is the phase transition.
In order to completely understand why some things burn while some melt we have to first understand the process of phase transition.
The phase transition is the phenomenon which describes the transition between solid, liquid and gases. At times it is also of utility in studying such phenomenon related to plasma state also. Please note that a single phase of a thermodynamic system pertaining to a state of matter will have uniform property. A phase transition is said to have occurred when certain properties of the medium change (like wax melting) due to changes in the external factors like temperature & pressure etc. The measurement of the conditions that led to this change is called phase transition.