Hydrogen in its metallic state (usually considered a nonmetal)
Lithium
Sodium
Potassium
Rubidium
Cesium
Francium
Rubidium is one of the alkali metals.
RTC, wikipedia.orgHydrogen in its metallic state (usually considered a nonmetal)
Lithium
Sodium
Potassium
Rubidium
Cesium
Francium
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