Cobalt: m. Gray, steely, strong, slightly malleable ductile metallic element. It is obtained by roasting the cobaltine, followed by reduction with aluminium. It is used in electroplating, dyes and in alloys with iron. Symbol, Co; N. A., 27; P. A., 58 ' 94. 60. Radioactive cobalt whose half-life is 5 ' 3 years. It is obtained by irradiation of oxide of cobalt in a stack. Used in radiation therapy and for the treatment of cancer.
