Thus Bunsen in 1860 discovered two new alkaline metals, Cæsium and rubidium.
He picked up a shard of rubidium that served as a paper weight and toyed with it.
Only potassium and rubidium have a greater activity than this, and theirs is only about one-thousandth that of uranium.
Lithia and fluorine are each present to the extent of about 5%; rubidium and caesium are sometimes present in small amounts.
At Pala it has been extensively mined for the preparation of lithium and rubidium salts.
In rubidium the lines Rb and Rb in the blue, and Rb in the red are almost equally specific.
Potassium has nine, rubidium has sixteen, in both cases radiating from a central globe.
Cæsium and rubidium are separated from potassium by fractional precipitation with platinum chloride.
The separation of lithium, cæsium, and rubidium is seldom called for, owing to their rarity.
rubidium occurs widely diffused in nature, but in very small quantities.
rubidium ru·bid·i·um (rōō-bĭd'ē-əm)
A soft metallic element of the alkali group. Atomic number 37; atomic weight 85.47; melting point 39.31°C; boiling point 688°C; specific gravity (solid) 1.532; valence 1, 2, 3, 4.
A soft, silvery-white metallic element of the alkali group. It ignites spontaneously in air and reacts violently with water. Rubidium is used in photoelectric cells, in making vacuum tubes, and in radiometric dating. Atomic number 37; atomic weight 85.47; melting point 38.89°C; boiling point 688°C; specific gravity (solid) 1.532; valence 1, 2, 3, 4. See Periodic Table.