Characteristic

Rubidium is a chemical element with the symbol Rb and atomic number 37. Rubidium is a very soft, silvery-white metal in the alkali metal group. Rubidium metal shares similarities to potassium metal and caesium metal in physical appearance, softness and conductivity.

Phase at STP:solid

Appearance:grey white

Melting point:312.45 K (39.30 °C, 102.74 °F)

Boiling point:961 K (688 °C, 1270 °F)

Density (near r.t.):1.532 g/cm³

when liquid (at m.p.):1.46 g/cm³

Triple point:312.41 K

Critical point:2093 K, 16 MPa (extrapolated)

Heat of fusion:2.19 kJ/mol

Heat of vaporization:69 kJ/mol

Molar heat capacity:31.060 J/(mol·K)

Application

Rubidium compounds are sometimes used in fireworks to give them a purple color. Rubidium has also been considered for use in a thermoelectric generator using the magnetohydrodynamic principle, where hot rubidium ions are passed through a magnetic field.

Rubidium has been used for polarizing 3He, producing volumes of magnetized 3He gas, with the nuclear spins aligned rather than random.

The resonant element in atomic clocks utilizes the hyperfine structure of rubidium's energy levels, and rubidium is useful for high-precision timing. It is used as the main component of secondary frequency references (rubidium oscillators) in cell site transmitters and other electronic transmitting, networking, and test equipment. 

Other potential or current uses of rubidium include a working fluid in vapor turbines, as a getter in vacuum tubes, and as a photocell component.

Rubidium-82 is used for positron emission tomography.

Rubidium_MSDS.pdf