37
Rb
85.468
Rubidium (Rb)
Element 37 · Period 5 · Group 1
alkali-metal
solid at room temp
s-block
About Rubidium
Highly reactive alkali metal. Used in atomic clocks and medical imaging.
Physical Properties
Atomic Mass
85.468 u
State at 25°C
Solid
Melting Point
39.31 °C
Boiling Point
688 °C
Density
1.532 g/cm³
Magnetism
Paramagnetic
Atomic Properties
Electron Configuration
[Kr] 5s¹
Electron Shells
2, 8, 18, 8, 1
Electronegativity
0.82
Atomic Radius
265 pm
Ionization Energy
403 kJ/mol
Oxidation States
+1
Discovery & History
Discovered By
Robert Bunsen
Discovery Year
1861
Named By
Robert Bunsen
Name origin: Latin: rubidus (deep red)
Frequently Asked Questions
- Is Rubidium a metal, nonmetal, or metalloid?
- Rubidium is classified as a alkali-metal.
- What state is Rubidium in at room temperature?
- Rubidium is a solid at standard room temperature (25°C).
- What is the atomic mass of Rubidium?
- Rubidium has an atomic mass of 85.468 atomic mass units (u).
- Who discovered Rubidium?
- Rubidium was discovered by Robert Bunsen in 1861.
- Where is Rubidium on the periodic table?
- Rubidium is element number 37, located in period 5 and group 1.