Question

A camper burned a piece of paper to start a campfire. is burning paper a physical or chemical change? why? 

If you said chemical, what are the reactants and products?
The ash has less mass than the paper, was mass conserved during the reaction? explain

Answer 1

A camper burning a piece of paper to start a campfire is a chemical change - the way you can think of this is to consider the fact that the paper cannot be put back together and has become ash, so this is therefore a chemical change. The carbon in the paper is oxidized into other chemical including carbon dioxide. Mass was conserved during this reaction because the mass is still the same, just in a different form.