Why is frying an egg an example of a chemical change

A Chemical change is any form of chemical reaction changing the state of the matter involved. When you fry an egg, you are making a reaction between the heat and the chemicals that make up the egg. Therefore once you have fried that egg, you have completed a chemical reaction. This is why it's a chemical change when you fry an egg.

A chemical change changes the substance itself. That means that you cannot go back to the original substance that you had before. A chemical change breaks or forms new bonds. 

When you fry an egg, you cant change it back to its liquid form. Now the egg looks different than it was before you fried it. And also, you cannot change it back to how it looked.