What is the name of the inorganic compound that has a pungent odor and is used in permanent wave solutions to open the cuticle layer?

The correct answer, ammonia, is an inorganic compound commonly used in permanent wave solutions due to its ability to raise the pH of the hair and help open the cuticle layer. This action is essential for the chemical process involved in perming hair, as it allows the solution to penetrate the hair shaft and alter its structure. Ammonia has a distinct pungent odor, which is characteristic and can be recognized easily during application.

In the context of chemical texturizing, ammonia serves a crucial role in preparing the hair for the waving or curling process. When applied, it helps break down the disulfide bonds in the hair's keratin structure, enabling the hair to reshape. After the hair is set into the desired style, neutralizing solutions typically contain ingredients that will restore the hair's natural pH and reform the disulfide bonds.

The other compounds listed do not serve the same function in this context. Calcium carbonate is primarily used in other applications, and while hydrogen peroxide is used in the neutralizing process of perms, its role is not to open the cuticle layer initially; it is more associated with providing oxidation. Formaldehyde is not commonly used in modern permanent wave formulations due to safety concerns and is more related to hair straight