Atomic Number
37
Element 37
Rubidium (Rb)
Rubidium is a chemical element with symbol Rb and atomic number 37. Rubidium is a soft, silvery-white metallic element of the alkali metal group, with a standard atomic weight of 85.4678.
Atomic Mass
85.468 u
Category
Alkali Metal
Period
5
Group
Group 1: alkali metals and hydrogen
Phase
solid
Density
1.532 g/cm3
Electron Shells
2, 8, 18, 8, 1
Atomic Structure
Protons: 37. Electrons: 37. Neutrons: Varies by isotope.
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹
Why Rubidium Matters
Rubidium helps connect atomic number 37, alkali metal behavior, period 5 trends, and electron shell structure. Its solid phase, atomic mass of 85.468 u, and electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ make it useful for comparing bonding patterns across the periodic table.
Discovery and Occurrence
Rubidium was discovered 1861 by Robert Bunsen, Gustav Kirchhoff. Rubidium is a chemical element with symbol Rb and atomic number 37. Rubidium is a soft, silvery-white metallic element of the alkali metal group, with a standard atomic weight of 85.4678.
Safety and Handling Context
Rubidium is in a highly reactive family. Pure alkali metals can react strongly with water, so demonstrations belong in controlled lab settings.
Related Elements
Frequently Asked Questions
- What is the atomic number of Rubidium?
- Rubidium has atomic number 37, which means a neutral atom has 37 protons and 37 electrons.
- What is the chemical symbol for Rubidium?
- The chemical symbol for Rubidium is Rb.
- What category is Rubidium in?
- Rubidium is classified as a alkali metal and sits in period 5 of the periodic table.
Explore Rubidium in 3D
Use the interactive table above to rotate atomic models, compare periodic trends, and move from Rubidium to neighboring elements without losing your place.