Yes, as it burns it reacts with the oxygen in the air to create new compounds. However, not all of the chemicals change.
Saw dust
The Average time a cigarette burns while being smoked by my calculations is between 5-10 minutes depending on the person...
sawdust that is piling up under a table - is a physical change
chemical change
A metal Surface being ground is a physical change, not a chemical change.
physical. the water being added simply soaks through the coffee, so there's no chemical change.
Drugs
Gasoline being poured into a tank is not a chemical change.
Being resistant to corrosion is a physical property of a material, not a physical or chemical change. It means that the material does not undergo chemical reactions with its environment that would cause it to deteriorate over time.
It depends on the purity. In some cases, when meth is manufactured, traces of some of the chemicals used to induce the chemical reactions necessary to create the meth are left on the meth itself. This can change the smell of it. Many people report that pure meth does not have much of a smell at all when smoked.
is cocaine worst being inhaled or smoked
burning of tree or wood is an irreversible chemical change