Does anyone know methods that scientists use to determine if a change was physical or chemical?

If there is no change in the chemical properties, it is a physical change.

Methods they use to determine physical changes:

-State in Matter change

-Difference of Size

If there is a change in the chemical composition, it is a chemical change.

Methods they use to determine chemical changes:

-Bubbling

-Color change

-Solid formation from mixing

-Heat given off

-New substance with different properties.