Chemical element · Atomic number 37
Rubidium
Rubidium in the periodic table: atomic number 37, electron configuration, atomic mass, physical data, oxidation states, media credit and visible sources.
Alkali metal
solid
85.468 u
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Atomic classification
Shell occupancy
Rubidium in the Bohr shell model
This shows the electron distribution of the neutral atom in a simplified shell model.
- K · n=1
- 2 electrons
- L · n=2
- 8 electrons
- M · n=3
- 18 electrons
- N · n=4
- 8 electrons
- O · n=5
- 1 electron
- Electron configuration
- [Kr]5s1
- Electrons per shell
- 2 · 8 · 18 · 8 · 1
- Group
- 1
- Period
- 5
- Block
- S
- Element category
- Alkali metal
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Physical and chemical properties
- Atomic mass
- 85.468 u
- Standard state
- solid
- Density
- 1.53 g/cm³
- Melting point
- 312.46 K
- Boiling point
- 961 K
- Electronegativity
- 0.82 (Pauling)
- First ionisation energy
- 4.177 eV
- Oxidation states
- +1
- Discovery
- 1861
Safety and periodic classification
Safety
Safe handling cannot be inferred from Rubidium's position in the periodic table alone. Laboratory, classroom and disposal decisions must follow the documentation for the exact material and its safety data sheet.
Position and comparison
Rubidium is in period 5, group 1 and the S block. Its direct neighbours by atomic number are Krypton and Strontium. The recorded Pauling electronegativity is 0.82. Periodic trends are compared only through the separately sourced neighbouring values.
Sources and scope
PubChem attributes element data to sources including IUPAC, NIST and IAEA. Quanta stores the referenced snapshot locally and leaves unknown values unavailable.