Chemical change, Physical change, or both?

Question

When a platinum wire is heated in a bunsen burner flame, the platinum gets red hot, but returns to its original appearance on cooling. Has the platinum wire undergone physical change, chemical change, or both when heated?

Answer 1

physical change

Answer 2

The wire has only undergone a physical change, as once the heat is removed the wire will go back to the exact same state it was before it was heated. Platinum and gold are not only rare, but extremely unreactive; these metals will only undergo chemical changes under intensely acidic or oxidative conditions.

Answer 3

Unless the platinum reacts with oxygen or other gases in the flame, it undergoes a physical change. ALl you've done is heat up the wire without causing any chemical bonds to change. The metal may have a phase change, but that is also physical. Chemically, you still have platinum wire.

Answer 4

CHEMICAL. Physical is what you do to a piece of paper when you rip it apart. You my have changed its appearance, but you have not changed the fact that it is paper, its identity. Its chemical composition has not changed. usually it's something like bending, breaking, cracking, splitting, etc. Chemical is when you change the molecular structure or something. Baking is a chemical reaction, believe it or not. Where do you think the air pockets in bread come from? Gas released because of a chemical reaction. plus the cake is turning from liquid to solid.

Answer 5

the platinum wire has only undergone physical changes i.e. temperature change. the chemical structure of the platinum has not change

Answer 6

Physical change only. The metal in the wire is not oxidized and the platnium does not undergo a chemical reaction with any other atoms or molecules.