Litmus paper being dipped into an acidic solution. Litmus paper is either blue (as here) or red. The blue form turns red in acids. The red form turns blue in alkalis | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Andrew Lambert Photography |
Taille de l’image : | 3563 px × 4909 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |