Rubidium is the second most electropositive of the stable alkali elements and liquefies at a temperature of 39.3 °C (102.7 °F). Like other group 1 elements, this metal reacts violently in water. In common with potassium and caesium this reaction is usually vigorous enough to ignite the liberated hydrogen. Rubidium has also been reported to ignite spontaneously in air. Also like other alkali metals, it forms amalgams with mercury and it can form alloys with gold, caesium, sodium, and potassium. The element gives a reddish-violet color to a flame, hence its name.
IUPAC Name: Rubidium
The MF of Rubidium (CAS NO.7440-17-7) is Rb.
                        
The MW of Rubidium (CAS NO.7440-17-7) is 85.47.
Synonyms of Rubidium (CAS NO.7440-17-7): Rubidium ; Rb ; Rubidio
Apperance: A soft silvery metal
Melting Point: 38-39 °C
Boiling Point: 686 °C
Density: 1.53 g/mL at 25 °C
Merck: 13,8363

 Rubidium (Latin: rubidus, deepest red) was discovered in 1861 by Robert Bunsen and Gustav Kirchhoff in the mineral lepidolite through the use of a spectroscope. Processing 150 kg of lepidolite yielded only a few grams for analysis. Rubidium metal was first produced by the reaction of rubidium chloride with potassium by Bunsen.

Historically, the most important use for Rubidium (CAS NO.7440-17-7) has been in research and development, primarily in chemical and electronic applications.
 In 1999 rubidium-87 was used to make a Bose-Einstein condensate, for which the discoverers won the 2001 Nobel Prize in Physics.
 Rubidium is easily ionized, so it has been considered for use in ion engines for space vehicles.
 Rubidium has also been considered for use in a thermoelectric generator using the magnetohydrodynamic principle, where rubidium ions are formed by heat at high temperature and passed through a magnetic field.

 Rubidium metal can be produced by reducing rubidium chloride with calcium among other methods. In 1997 the cost of this metal in small quantities was about US$25/gram.

Reported in EPA TSCA Inventory.

Moderately toxic by intraperitoneal route. A very reactive alkali metal (more reactive than potassium or cesium). In the body, rubidium substitutes for potassium as an intracellular ion. The ratio of Rb/K intake is important in the toxicology of rubidium. A ratio above 40% is dangerous. In rats, a failure to gain weight is the first symptom, followed by ataxia and hyperirritability. Symptoms include: skin ulcers, poor hair coat, sensitivity, and extreme nervousness leading to convulsions and death.A very dangerous fire and explosion hazard when exposed to heat or flame or by chemical reaction with oxidizers. Ignites on contact with air, oxygen, and halogens. Ignites spontaneously on contact with water. Reaction with water, moisture, or steam forms explosive hydrogen gas, which then ignites. Explodes in contact with liquid bromine. Can react explosively with air, halogens, mercury, nonmetals, vanadium chloride oxide, moisture, acids, oxidizers. Violent reaction with vanadium trichloride oxide (at 60°C), Cl₂O₂, P. Molten rubidium ignites in sulfur vapor and reacts vigorously with carbon. RbOH is more basic than KOH. Storage and handling: Keep under benzene, petroleum, or other liquids not containing gaseous O₂. When heated to decomposition it emits toxic fumes of Rb₂O. See also SODIUM and POTASSIUM SODIUM ALLOY.Safety information of Rubidium (CAS NO.7440-17-7):
Hazard Codes  Xi,C,F
Risk Statements 
36/37/38 Irritating to eyes, respiratory system and skin
34 Causes burns
14/15 Reacts violently with water, liberating extremely flammable gases
Safety Statements 
26 In case of contact with eyes, rinse immediately with plenty of water and seek medical advice
36/37/39 Wear suitable protective clothing, gloves and eye/face protection
43 In case of fire, use ... (indicate in the space the precise type of fire-fighting equipment. If water increases the risk add - Never use water)
45 In case of accident or if you feel unwell, seek medical advice immediately (show label where possible)
RIDADR  UN 2031 8/PG 2
WGK Germany  3
RTECS  VL8500000
HazardClass  8
PackingGroup  III

DOT Classification:  4.3; Label: Dangerous When Wet

 Rubidium is very soft and highly reactive, with properties similar to other elements in group 1, such as very rapid oxidation in air. Its compounds have chemical and electronic applications. Rubidium metal is easily vaporized and has a convenient spectral absorption range, making it a frequent target for laser manipulation of atoms.
 Rubidium is not known to be necessary for any living organisms. However, like caesium, rubidium ions are handled by living organisms in a manner similar to potassium: it is actively taken up by plants and by living animal cells.