Rb
Rubidium
Alkali MetalAtomic Number: 37 • Atomic Mass: 85.4680 u • Period: 5 • Group: 1
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹
Phase: Solid
Electronegativity: 0.82
Physical & Chemical Properties
Physical Properties
- •Soft, silvery-white metallic element
- •Very low melting point (312.46 K or 39.31°C)
- •One of the most electropositive elements
- •High reactivity requires storage under mineral oil
- •Liquid at slightly above room temperature
Melting Point
312.46 K (39.31 °C, 102.76 °F)
Boiling Point
961 K (687.85 °C, 1270.13 °F)
Density
1.532 g/cm³
Electronegativity
0.82 (Pauling scale)
Chemical Properties
- •Extremely reactive, especially with water
- •Can ignite spontaneously in air
- •Forms ionic compounds with +1 oxidation state
- •Stronger reducing agent than potassium
- •Compounds generally soluble in water
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹Electron configuration describes how electrons are distributed in atomic orbitals, showing how they are arranged in energy levels and subshells.