How can paper that has already been used be physically changed

We just started a new lesson in chemistry and everyone hates it and i dont get it one bit. i hate school. h el p.balanced equationc3h8+5o2-> 3co2+4h2o1.) if you start with 14.8g of propane(c3h8) and 3.44g of oxygen, which is the limiting reactant -check my answer 2.)what mass of excess reagent is left over? 3.)what mass of carbon dioxide can be made? 4.)what mass of water is produced?

The reaction q+r2=r2q is found to be first order in r2 and

What are transitions between a liquid and a solid called? identify which way they are transitioning