Redseal Hairstyling License Practice Test

Which of the following best describes the action of hydrogen bonds in hair?

1. They strengthen the hair

2. They can only be broken by water or heat

3. They are irreversible

4. They form chemical bonds

The correct answer is: They can only be broken by water or heat

The action of hydrogen bonds in hair is primarily characterized by their ability to be broken and reformed. These bonds are weak attractions that occur between the hydrogen atoms attached to one electronegative atom and another electronegative atom in the nearby structure. In the context of hair, these hydrogen bonds can indeed be broken by water, as the molecule can disrupt the interactions that hold the hair strands together, allowing for flexibility and changes in shape. Additionally, heat can also disrupt these bonds, leading to temporary styling changes, such as curling or straightening. The nature of hydrogen bonds allows for reversible changes in the hair's structure. When the hair dries, these bonds can re-establish themselves, restoring the hair to its previous shape. This reversible action is significant because it allows for versatility in hairstyling, where textures and shapes can change with just the right exposure to moisture or heat. While some options suggest strengthening hair or the formation of chemical bonds, hydrogen bonds do not strengthen the hair in the way that covalent or disulfide bonds do, and they are certainly considered reversible rather than irreversible. Furthermore, they are not classified as chemical bonds; instead, they are part of the weaker attractions that enable hair to maintain its structure and flexibility.