Expert: Sherman D. - 10/24/2004

Question
Can you please explain to me why:
drawing copper into a wire is a chemical or physical change.
heating a copper wire till it glows is a chemical or physical change.
the melting of solder is a chemical change or a physical change

Also, is dissolving sugar in water a chemical change because you can't see the sugar anymore?What counts as a chemical change and what counts as a physical change.
This has been one topic that I just can't fathom.
Thank you so much for your help.You have always been a great help in the past.I'm opptimistic you can help me understand this concept as well.

Answer
I believe this will be easy to explain.

Not certain what you mean by drawing copper, but i believe since the state of the copper isn't being changed from one state to another, this seems to be a chemical change.

I believe most of the time if a physical change isn't involved, then it is most likely a chemical change.

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Light is emitted. Sometimes energy is released by bond-forming reactions in the form of light. This occurs in most combustion reactions. Living things that glow in the dark- such as fireflies, funguses, and deep sea creatures- produce light without heat, using chemical reactions.

Found at http://antoine.frostburg.edu/chem/senese/101/reactions/symptoms.shtml

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Melting Solder only change the Solder from Solid to Liquid, but the solder is still solder, it just changes its state of matter, so this is physical change.

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Dissolving sugar in water (sugar molecules are dispersed within the water, but the individual sugar molecules are unchanged.

Found at http://antoine.frostburg.edu/chem/senese/101/matter/faq/physical-chemical.shtml

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Physical Change means that the solid, liquid, or gas becomes a different state but does not change its element.

Chemical change is any change that results in the formation of new chemical substances. At the molecular level, chemical change involves making or breaking of bonds between atoms.