37
Rb
Alkali metal

Rubidium

Atomic number 37 · Period 5 · Block S

Rb · Rubidium
Mendeleev.com

Understanding the element

Rubidium (Rb) is chemical element 37. It belongs to the alkali metals, and its reference state at room temperature is a solid. Those basic facts are a useful starting point for its chemistry and applications.

Where do we encounter it?

In practice, it turns up most often in scientific research, atomic clocks and photocells.

scientific researchatomic clocksphotocells
Standard atomic weight85.4678(3)

What its position in the table tells us

Rubidium sits in period 5, group 1 and the S block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.

Worth remembering
Rubidium has a characteristic place in the periodic table that helps explain both its chemistry and its practical uses

Scientific sources

Element identity
Atomic number37
Group1
Period5
BlockS
CategoryAlkali metal
PhaseSolid