radium

Name radium
Symbol Ra
Atomic Weight 226.03
Atomic Number 88
CAS ID 7440-14-4
Group Number 2
Group Name Alkaline Earth Metal
Period Number 7
Origin of Name Latin, radius = "ray"
Year Discovered 1898
Discovery Credits Pierre and Marie Curie at Paris, France.
Class Metallic
Color Metallic
Standard State Solid at 77 F & 298 K
Description Radioactive element found naturally in uranium and thorium ores. Silvery, lustrous, soft. Annual production 100 gm. Formerly used in cancer therapy and for luminous paint; both used now rare. Reacts with oxygen and water.

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