Litmus pH indicator in acid (left) and base (right). Litmus is a water soluble mixture of dyes extracted from lichens. When used as a test,acids below pH 4.5 turn the dye red and bases above pH 8.3 turn the dye blue | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Chillmaid, Martyn F. |
Taille de l’image : | 3840 px × 5760 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |