Colorado Cosmetology Written Practice Exam

Ammonium thioglycolate is a type of chemical used in hair relaxers. The pH scale measures the acidity or basicity of a substance, and its values range from 0 to 14. A pH of 7 is considered neutral, with values below 7 being acidic and above 7 being basic.

In this question, the correct answer is A, 4.5-7.0. This means that ammonium thioglycolate has a slightly acidic pH, making it gentler on the hair and scalp.

The other options, B, C, and D, are all in the basic range of the pH scale. Using a relaxer with a pH in these ranges can cause damage to the hair and scalp.

Option B, 7.0-8.0, is a slightly higher pH than neutral, which can still be damaging to the hair. Option C, 9.0-9.6, is in the high basic range and can cause considerable damage to the hair. Finally, option D, 9.6-10.0, is in the extreme basic range and can cause severe damage to the hair and scalp.

In summary, the correct answer