Final answer:
The process of hydroxide relaxers permanently straightening hair involves the disruption and reformation of disulfide bonds using a reducing agent and an oxidizing agent. Ammonium thioglycolate is usually used to reduce and rupture the disulfide cross-links, while hydrogen peroxide helps reform the disulfide bonds in their new positions.
Step-by-step explanation:
In Chemistry, the process by which hydroxide relaxers permanently straighten the hair is through the disruption and reformation of disulfide bonds. Relaxers remove a sulfur atom from a disulfide bond, converting it into a lanthionine bond. This process involves the use of a basic reducing substance, usually ammonium thioglycolate, to reduce and rupture the disulfide cross-links. Then, an oxidizing agent, such as hydrogen peroxide, is added to reform the disulfide bonds in their new positions.