pH levels are a measure of

• A. Temperature
• B. Color
• C. Acid or alkaline
• D. Viscosity

Answer: (C)

pH levels measure how acidic or alkaline a solution is. This comes from the concentration of hydrogen ions in the liquid, and the pH scale runs from 0 to 14 with 7 as neutral. Values below 7 indicate increasing acidity, while values above 7 indicate increasing alkalinity. Temperature doesn’t define pH, though readings can shift slightly with temperature. Color changes are used by indicators to reveal pH, but color itself isn’t the measurement. Viscosity is about how thick a liquid is, not its acidity or basicity. In hair and scalp care, understanding pH helps explain why products aim for a mildly acidic range (around 4.5–5.5) to keep the hair cuticle closed and the scalp balanced.