Sugar burns when heated on a skillet physical or chemical change

Chemical change:

The change in which substance lose the identity is called chemical change. For example the rust on iron; in this change iron is oxidized into iron oxide.  

In general chemical changes have following four changes:

1.  Formation of a gas

2.  formation of a solid,  

3.formation of new substances,  

4.  Heat produced or absorbed.

Physical change:

The change in which substance does not lose the identity is called physical change. For example; the conversion of water into ice. In this water did not lose its identity.  

when sugar burns it changed into CO2 and H2O thus according to the above definition it is an example of chemical change