To derive is defined as to come from, be created from or be developed out of something else. An example of derive is when you get the idea for a new fund raising event based on the event the previous year.
Rubidium: geological information. Rubidium is far too reactive to be found as the free metal in nature. It is relatively rare, although it is the 16th most abundant element in the earth's crust. Rubidium is present in some minerals found in North America, South Africa, Russia, and Canada. It is found in some potassium minerals (lepidolites, biotites, feldspar, carnallite), sometimes with caesium as well.
Bunsen and Kirchhoff named the element cesium, from the Latin word âcaesiusâ meaning sky blue, after the blue lines they saw in the spectrum. The Latin spelling is still reflected in British English where cesium is spelt âcaesium.â. In 1861 Bunsen and Kirchhoff also discovered rubidium by the same method.