| Melting sulphur. A crucible with powdered sulphur, S, is heated over a Bunsen burner flame. It first melts to a straw-yellow liquid and then darkens to a red-brown colour. | |
| Licence : | Droits gérés |
| Crédit: | Science Photo Library / Turtle Rock Scientific |
| Taille de l’image : | 8000 px × 3236 px |
| Model Release : | Non requis |
| Property Release : | Non requis |
| Restrictions : | - |