During a chemical service, which bonds in the cortical layer must be neutralized for permanent reformation?

In the context of permanent reformation during a chemical service, it is essential to understand the nature of the bonds present in hair. The hair shaft has a cortical layer where strong structural bonds play a significant role in defining the hair's shape and strength.

Hydrogen bonds, while weaker and temporary, do help maintain hair's shape but are not the primary bonds that require neutralization for permanent changes. Sulfur bonds, specifically disulfide bonds, are strong covalent bonds formed between the sulfur atoms in the amino acids of keratin, the primary protein in hair. During chemical services such as perming, these disulfide bonds are broken to reshape the hair. To establish a new shape and ensure the hair retains that structure after the chemical service, these bonds need to be neutralized. This process ensures that the hair is set in its new configuration, resulting in long-lasting curls or waves.

The other options do not directly relate to the chemical processes involved in hair reformation during a perm or similar treatments, emphasizing the importance of hydrogen and sulfur bonds in achieving the desired results in permanent hair services.