Physical Process:
* Kneading the dough: This involves applying force to the dough, changing its shape and texture. This is a physical change because the composition of the dough remains the same. You're not creating new substances, just rearranging existing ones.
Chemical Process:
* Baking the dough: When the dough is heated in the oven, several chemical reactions occur:
* Yeast fermentation: The yeast in the dough breaks down sugars into carbon dioxide gas, which causes the dough to rise.
* Starch gelatinization: The heat causes the starch molecules in the flour to absorb water and swell, giving the bread its structure.
* Maillard reaction: This is a complex series of reactions between sugars and amino acids in the dough, responsible for the browning and flavor of the crust.
Key Differences:
* Physical changes alter the appearance or form of a substance, but not its chemical composition.
* Chemical changes involve the formation of new substances with different properties.
Let me know if you'd like more examples!
