re:mineral,ore,rock,metal

From: edwin (edwin2b_at_yahoo.com-dot-hk.no-spam.invalid)
Date: 12/29/04 

Date: 29 Dec 2004 04:28:01 -0600

ok~thx you very much.You help me a lot... :wink:
But I still have some questions to consult with you>..

1) Can we say that "because this is a chemical change , the reactants
must involve the chemical property of themselves unless this is
physical change so that the property for the reactants is physical
property.

In other words , chemical change
must correspond with
[color=red:8767c4163c]chemical property [/color:8767c4163c]to make
agreement ,
and vice versa.....then [color=darkblue:8767c4163c]physical change
[/color:8767c4163c]must correspond with
[color=blue:8767c4163c]physical property [/color:8767c4163c]also to
make agreement . Is it
correct??

2)Must the original reactants disappear in chemical property/change??

3)Last question,

   sugar+water=sugar water (physical change)

   calcium oxide+water=calcium hydroxide (chemical change)

I don't understand both are doing dissloving but why the process of
producing sugar water is physical change and the other one is
chemical change...please help me at all..thx:)

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