Elemental potassium metal being cut with a scalpel. Potassium has the atomic number 19, and is a very soft, highly reactive alkali metal. When cut with a scalpel, the shiny exposed metal surface reacts rapidly with oxygen and water in the air. When potassium metal is dropped into water, the heat from the reaction is sufficient to melt it into a ball, and the reaction produces sodium hydroxide and hydrogen gas. The hydrogen is ignited by the heat, and burns with potassium's characteristic lilac flame. The indicator phenolphthalein has been added to the water, which turns pink due to the presence of the strongly alkaline potassium hydroxide. | |
Licence : | Droits gérés |
Crédit : | Science Photo Library |
Model Release : | Disponible |
Property release : | Non requis |
Durée : | 14 Secondes |
Aspect ratio : | 16/9 |
Restrictions : | - |