Litmus paper being dipped into an alkaline solution. Litmus paper is either red or blue (as here). The red form turns blue in alkalis. The blue form turns red in acids | |
Licence : | Droits gérés |
Crédit: | Science Photo Library |
Taille de l’image : | 4500 px × 4500 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |