Are the following physical or chemical changes.
1.lighting a match
2.cooking waffles
3.baking a cake

Chemical reactions because the chemical formula is changed in the reaction

They are all chemical changes. Think of a chemical change as you can never get something back to the way it was. (A lit match can't be turned back into a new one, waffles can't be turned back into waffle mix, and a cake can't be turned back into cake batter.)

Physical change would be something like slicing cheese or evaporating water. (The sliced cheese is still cheese, and the water turns into steam which can then be turned back into a liquid and it's still water - just in the air.)

They are like other investigations? say there was a murder u have to do blood test and finger prints which run through a lab. 

Rn in the right answer