R

Rubidium

IUPAC: Rubidium

Rb Elements CAS 7440-17-7
Quick Reference
Formula / NotationRb
CAS Number7440-17-7
Molecular Weight85.47
Melting Point39.3
Boiling Point688.0
Density1.53
SolubilityReacts violently with water
AppearanceSoft, silvery-white metal
Also Known AsRb, rubidium metal
CategoryElements

What is Rubidium?

Rubidium is a soft, silvery-white alkali metal, atomic number 37. Highly reactive - ignites spontaneously in air and reacts explosively with water. Used in atomic clocks and as getter in vacuum tubes.

Formula & Notation

Rb

IUPAC Name: Rubidium

Other Names / Synonyms: Rb, rubidium metal

Properties & Characteristics

Atomic number: 37. Atomic mass: 85.468 g/mol. Period 5, Group 1. Melting point: 39.3 C. Boiling point: 688 C. Density: 1.53 g/cm3. Electronegativity: 0.82. Oxidation state: +1. Two natural isotopes: Rb-85 (72.2%) and Rb-87 (27.8%, radioactive, t1/2=49 Gyr).

Physical Data

PropertyValue
Melting Point39.3
Boiling Point688.0
Density1.53
Molecular Weight85.47
SolubilityReacts violently with water
AppearanceSoft, silvery-white metal

Uses & Applications

Atomic clocks (rubidium frequency standard). Photoelectric cells. Vacuum tube getter. Research in quantum mechanics (Bose-Einstein condensates). Rubidium vapor for magnetometers.

Safety Information

Reacts violently with water producing H2 and RbOH (fire/explosion). Ignites spontaneously in air. Causes severe chemical burns. Store in dry mineral oil or sealed under inert gas. More reactive than potassium.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Rubidium
Formula Rb
CAS Number 7440-17-7
Molecular Weight 85.47
Category Elements
Synonyms Rb, rubidium metal

Frequently Asked Questions

Rubidium is a soft, silvery-white alkali metal, atomic number 37. Highly reactive - ignites spontaneously in air and reacts explosively with water. Used in atomic clocks and as getter in vacuum tubes.

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