Question

can you explain me why tearing of paper is a physical change and burning of paper a chemical change?

Answer 1

physical;occur when objects undergo a change that does not change their chemical nature 
therefore,tearing a paper is a physical change because when we tear paper in to 2 or more than 2 parts the chemical nature of paper does not change
chemical: there is a chemical reaction that, changes its "appearance"
therefore,burning a paper is a chemical change because ,after burning paper the appearance of paper is changes.