When you boil an egg, the egg "white" changes from clear to white. The egg also becomes "hard boiled." What type of changes are occurring in the egg?
A.Chemical
B.Neither physical nor chemical
C.Physical
D.Physical and Chemical
A chemical change occurs when one or more substances are changed into different products. (an 8th grade definition). I want to "pick" on you a little even though I suspect you wrote the question exactly as you received it. I want to point out that the word clear is not the same as colorless. The egg white changed from colorless and clear (clear--meaning not cloudy or turbid) to an opaque white substance. It's opaque because you can't see through it. I suspect some physical changes occurred, also, but it would be difficult to distinguish them from the chemical ones.
Thanks.
The correct answer is both.
The correct answer is D. Physical and Chemical changes are occurring in the egg when it is boiled.
Explanation:
When you boil an egg, both physical and chemical changes take place. Let's break it down:
1. Physical Change: The egg white changes from clear to white. This change is a physical one because the composition of the egg white remains the same, but its appearance changes. The heat causes the proteins in the egg white to denature, unfold, and form new bonds, which results in the change in color and texture.
2. Chemical Change: The egg becomes hard-boiled. This is a chemical change because the heat causes chemical reactions to occur within the egg. As the temperature increases, the proteins in the egg undergo a process called coagulation. The proteins bond together, forming a solid matrix, and this solidification is irreversible, resulting in a hard-boiled egg.
In summary, boiling an egg involves both physical changes (change in appearance) and chemical changes (protein denaturation and coagulation) occurring simultaneously.