|
37
Rb
85.47
|
| Classification: | Rubidium is an alkali metal |
| Color: | silvery-white |
| Atomic weight: | 85.468 |
| State: | solid |
| Melting point: | 39.3 oC, 312.45 K |
| Boiling point: | 690 oC, 963 K |
| Shells: | 2,8,18,8,1 |
| Electron configuration: | [Kr] 5s1 |
| Density @ 20oC: | 1.53 g/cm3 |
| Atomic volume: | 55.9 cm3/mol |
| Structure: | bcc: body-centered cubic |
| Hardness: | 0.3 mohs |
Discovery of Rubidium
Rubidium was discovered in 1861 in the mineral lepidolite by Robert Bunsen and Gustav Kirchhoff using spectroscopic analysis.
The element name comes from the Latin word 'rubidius' meaning deepest red.
The name was given because Bunsen and Kirchhoff identified the presence of a new element in their sample through two ruby red spectroscopic lines.
Appearance & Characteristics
Rubidium (and then cesium) reacting with water.
Harmful effects:
Rubidium is not known to be toxic.
Characteristics:
Rubidium is a soft, silvery-white metallic element. It is solid at room temperature but melts easily, at 39.3 oC. Like the other group 1 metals, rubidium reacts violently in water, forming corrosive rubidium hydroxide (RbOH) and hydrogen gas, which is ignited by the heat of the reaction. Rubidium can also ignite spontaneously in air. It forms alloys with cesium, gold, sodium, and potassium and it forms amalgams with mercury. Rubidium burns with a reddish-violet flame color.
Rubidium is used in photocells, as a getter (remover of trace gases) in vacuum tubes and as working fluid in vapor turbines. Rubidium-87 is slightly radioactive and has been used extensively in dating rocks. Rubidium compounds give a purple color in fireworks. Rubidium salts are used in glasses and ceramics.
Rubidium is not known to be toxic.
Characteristics:
Rubidium is a soft, silvery-white metallic element. It is solid at room temperature but melts easily, at 39.3 oC. Like the other group 1 metals, rubidium reacts violently in water, forming corrosive rubidium hydroxide (RbOH) and hydrogen gas, which is ignited by the heat of the reaction. Rubidium can also ignite spontaneously in air. It forms alloys with cesium, gold, sodium, and potassium and it forms amalgams with mercury. Rubidium burns with a reddish-violet flame color.
Uses of Rubidium
Rubidium is used in photocells, as a getter (remover of trace gases) in vacuum tubes and as working fluid in vapor turbines. Rubidium-87 is slightly radioactive and has been used extensively in dating rocks. Rubidium compounds give a purple color in fireworks. Rubidium salts are used in glasses and ceramics.
Abundance & Isotopes
Abundance earth's crust: 90 parts per million by weight, 21 parts per million by moles
Abundance solar system: 30 parts per billion by weight, 0.4 parts per billion by moles
Cost, pure: $1200 per 100g
Cost, bulk: $ per 100g
Source: The main ore of rubidium is lepidolite which contains 1.5% rubidium. Rubidium is usually obtained as a by product of lithium production. Rubidium metal can also be produced by reducing rubidium chloride with calcium.
Isotopes: Rubidium has 29 isotopes whose half-lives are known, with mass numbers 74 to 102. Of these, one is stable: rubidium-85. Rubidium-87, which comprises almost 28% of naturally occurring rubidium, is slightly radioactive, with a half-life of 49 billion years.
Abundance solar system: 30 parts per billion by weight, 0.4 parts per billion by moles
Cost, pure: $1200 per 100g
Cost, bulk: $ per 100g
Source: The main ore of rubidium is lepidolite which contains 1.5% rubidium. Rubidium is usually obtained as a by product of lithium production. Rubidium metal can also be produced by reducing rubidium chloride with calcium.
Isotopes: Rubidium has 29 isotopes whose half-lives are known, with mass numbers 74 to 102. Of these, one is stable: rubidium-85. Rubidium-87, which comprises almost 28% of naturally occurring rubidium, is slightly radioactive, with a half-life of 49 billion years.
Energies
Specific heat capacity: 0.363 J g-1 K-1
Heat of fusion: 2.192 kJ mol-1
1st ionization energy: 403 kJ mol-1
3rd ionization energy: 3859.4 kJ mol-1
Heat of fusion: 2.192 kJ mol-1
1st ionization energy: 403 kJ mol-1
3rd ionization energy: 3859.4 kJ mol-1
Heat of atomization: 81 kJ mol-1
Heat of vaporization : 72.216 kJ mol-1
2nd ionization energy: 2632.1 kJ mol-1
Electron affinity: 46.885 kJ mol-1
Heat of vaporization : 72.216 kJ mol-1
2nd ionization energy: 2632.1 kJ mol-1
Electron affinity: 46.885 kJ mol-1
Oxidation & Electrons
Shells: 2,8,18,8,1
Minimum oxidation number: 0
Min. common oxidation no.: 0
Electronegativity (Pauling Scale): 0.82
Minimum oxidation number: 0
Min. common oxidation no.: 0
Electronegativity (Pauling Scale): 0.82
Electron configuration: [Kr]5s1
Maximum oxidation number: 1
Max. common oxidation no.: 1
Polarizability volume: 47.3 Å3
Maximum oxidation number: 1
Max. common oxidation no.: 1
Polarizability volume: 47.3 Å3
Reactions & Compounds
Reaction with air: vigorous, ⇒ RbO2
Reaction with 15 M HNO3: vigorous, ⇒ RbNO3, H2, Nox
Oxide(s): Rb2O, Rb2O2, Rb2O3, RbO2 (rubidium superoxide)
Hydride(s): RbH
Reaction with 15 M HNO3: vigorous, ⇒ RbNO3, H2, Nox
Oxide(s): Rb2O, Rb2O2, Rb2O3, RbO2 (rubidium superoxide)
Hydride(s): RbH
Reaction with 6 M HCl: vigorous, ⇒ H2, RbCl
Reaction with 6 M NaOH: vigorous, ⇒ H2, RbOH
Chloride(s): RbCl
Reaction with 6 M NaOH: vigorous, ⇒ H2, RbOH
Chloride(s): RbCl
Radius
Atomic radius: 248 pm
Ionic radius (2+ ion): pm
Ionic radius (2- ion): pm
Ionic radius (2+ ion): pm
Ionic radius (2- ion): pm
Ionic radius (1+ ion): 166 pm
Ionic radius (3+ ion): pm
Ionic radius (1- ion): pm
Ionic radius (3+ ion): pm
Ionic radius (1- ion): pm
Conductivity
Thermal conductivity: 58.2 W m-1 K-1
Electrical conductivity: 47.8 x 106 S m-1
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