noun
- a soft, silvery-white metallic chemical element that is highly reactive and belongs to the alkali metal group
Usage: chemistry
Examples
- Rubidium is the second most electropositive element after cesium.
- The scientist studied the properties of rubidium in the laboratory.
- Rubidium has the atomic number 37 on the periodic table.
- When exposed to air, rubidium quickly forms a dark oxide coating.
- Atomic clocks often use rubidium as a frequency standard.
- Rubidium compounds produce a distinctive red-violet flame color.