posted by Jim .
Can an object experience both a physical and chemical change at the same time?
Probably the same atom can not; however, it should be possible that a sequence of physical change then a chemical change could occur and some atoms/molecules could be undergoing one while other atoms were undergoing the other.
I don't see why not. For example a piece of carbon (charcoal) burning in an oxygen atmosphere. The carbon atoms will undergo a physical change in the they start in the solid phase and end up in the gas phase as CO2, and also undergo a chemical change.