When you place a raw egg in boiling water and cook it for two minutes, several changes occur to the egg. Here's a description of what happens:
Coagulation of proteins: As the egg is heated, the proteins in the egg white denature and coagulate, forming a solid mass. This process transforms the transparent egg white into a white, opaque substance.
Solidification of yolk: The heat also causes the yolk to solidify to some extent, although it may remain slightly runny at the center. The extent of solidification depends on the cooking time.
Increase in temperature: The heat from the boiling water raises the temperature of the entire egg, including the yolk and the egg white.
Pressure build-up: As the water boils, it undergoes a phase change from liquid to gas, producing steam. This steam builds up pressure inside the eggshell.
It's important to note that boiling an egg for only two minutes will likely result in a soft-boiled or lightly cooked egg, where the yolk is still somewhat runny. The precise consistency can vary depending on factors such as egg size, initial temperature, and altitude. If you prefer a harder-boiled egg, you would need to increase the cooking time.