Toaster element become red hot

First the bread after heated with high temperature, water evaporate and the outer part becoming carbonized. So a toaster is formed. You cannot by putting water to the toaster to convert it back to a bread. The browning part will never change back to white. It is a chemical reaction not physical one. However for a light filament, when you switch it on, it will glow to red hot emitting light and when you turn it off, it will return to a filament, the metal does not change a bit. It is a physical change.

2009-03-14 10:34:05 補充：
instead "You cannot by putting...", change to "You cannot put water..." sorry type it in hurry.

多士經過焗le個程序,佢入面d粒子只係熱左,但係都係同一樣既野

對於lamp filament glowing ,我覺得係化學反應,因為
燈glowing既時候電能change into 熱能