Yes, frying an egg is indeed a chemical reaction. When you heat an egg, the proteins in the egg white (albumen) and yolk undergo a transformation.
Initially, these proteins are in a liquid state. As they are subjected to heat, they start to denature, meaning their structure unravels. This process occurs around 140°F (60°C) and causes the proteins to bond with each other, leading to a firm structure. This change from liquid to solid is an example of a permanent chemical change, as the original ingredients cannot be reverted to their raw state.
Additionally, the color change from translucent to opaque and the transformation in texture also signify chemical changes taking place. Therefore, while it may seem like a simple cooking process, frying an egg is a fascinating demonstration of chemistry in action.