pH test. School student using universal indicator to test the pH level of the contents of a test tube. Here, the green universal indicator has turned

---

pH test. School student using universal indicator to test the pH level of the contents of a test tube. Here, the green universal indicator has turned red, indicating that the contents of the test tube is acidic.

---

Size: 3431px × 5125px
Photo credit: © TREVOR CLIFFORD PHOTOGRAPHY/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: acid, acidic, acidity, apparatus, caucasian, change, chemical, chemistry, child, color, color-change, colour, colour-change, device, education, equipment, experiment, experimenting, female, girl, glasses, goggles, human, indicator, lab, laboratory, liquid, people, person, ph, pipette, pipetting, red, safety, school, schoolgirl, science, solution, student, test, test-tube, testing, tube, universal, white, young