Is burning of wood a reversible or irreversible change

burning of wood is an irreversible change bcoz wood after burning wood converted to ashes cannot be converted back to wood nd its chemical composition also changes

can you reverse the ashes back into wood? If you can't then it is irreversible

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.