a soft silvery metallic element of the alkali metal group; burns in air and reacts violently in water; occurs in carnallite and lepidolite and pollucite
any oxide of rubidium, but especially the yellow solid Rb2O; it is a strong base, reacting strongly with water to form the hydroxide and with acids to form normal salts
geological dating based on the proportions of radioactive rubidium into its decay product strontium; radioactive rubidium has a half-life of 47,000,000,000 years
Method of estimating the age of rocks, minerals, and meteorites from measurements of the amount of the stable isotope strontium-87 formed by the decay of the unstable isotope rubidium-87 that was present in the rock at the time of its formation. The method is applicable to very old rocks because the transformation is extremely slow: the half-life, or time required for half the initial quantity of rubidium-87 to disappear, is approximately 48.8 billion years. See also dating
rubidium
Silbentrennung
ru·bid·i·um
Aussprache
Etymologie
() A New Latin word derived by German chemist R. W. Bunsen in 1861, from Latin rubidus (“red”) because its spectrum has two red lines.Chambers Dictionary of Etymology, Robert K. Barnhart (ed.), Chambers, 1988