On boiling an egg, why does the outer part become opaque and white?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. The heat causes denaturation, hardening the albumin and colouring it opaque white.
When an egg is boiled, the heat causes the proteins in the egg white (albumin) to denature, meaning they lose their natural structure. These unfolded proteins then bond together to form a solid, firm network. This process makes the egg white turn from transparent to opaque and white due to the scattering of light by the tightly packed protein structure, resulting in the hardening of the outer part.