The different types of energy include thermal energy, radiant energy, chemical energy, nuclear energy, electrical energy, motion energy, sound energy, elastic energy and gravitational energy.
you could use any of these.
Because a physical change does not change the substance's chemical properties
An example of a chemical reaction like sugar's chemical formula is C6H12O6 and if we apply heat to it and it burns it will now become just carbon ashes C
Elements that are found in potassium oxide is oxygen.
Non metals and metollids in periodic tables are the same how this helps ;)